Error in gasEstimation

Followed the gas estimation tutorial here: https://docs.mantle.xyz/network/for-devs/tutorials/estimating-transaction-fees

Warpped the gas estimation into:

`
const ethers = require("ethers")
const mantleSDK = require("@mantleio/sdk");

module.exports.getEstimateGas = async (tx) => {
const l2RpcProvider = new ethers.providers.JsonRpcProvider("https://rpc.testnet.mantle.xyz")
try{
// By calling the BVM_GasPriceOracle contract method l1basefee()
const gasPrice = await mantleSDK.getL1GasPrice(l2RpcProvider);
const decimals = await mantleSDK.decimals(l2RpcProvider);
const scalar = await mantleSDK.scalar(l2RpcProvider);
const gasUsed = await mantleSDK.overhead(l2RpcProvider);
// L1RollupFee
const l1RollupFee = gasPrice.mul(gasUsed).mul(scalar).div(10**decimals)

    // L2TxnFee
    const l2Gas = await l2RpcProvider.estimateGas(tx)
    const l2GasPrice = await l2RpcProvider.getGasPrice()
    const l2TxnFee = l2GasPrice.mul(l2Gas);
    
    // Total estimated Gas Fee
    const totalEstimatedGasFee = l1RollupFee.add(l2TxnFee);
    console.log('Total estimated Gas Fee:', totalEstimatedGasFee.toString());
    return { success: true, estimatedGas: totalEstimatedGasFee }
} catch (error) {
    console.error('Error estimating gas:', error);
    return { success: false }
}

}
`

If using a fake tx, the getEstimateGas function can be successfully invoked:

`const { getEstimateGas } = require('./gas_helper');
const ethers = require("ethers")

const tx = {
to: "0xdEc3262D5EADbbD946AdbB48a2A07ABe15B0AB83",
value: ethers.utils.parseEther("0.01"),

};

(async () => {
try {
const result = await getEstimateGas(tx);
console.log('Gas Estimate:', result);
} catch (error) {
console.error('Error:', error);
}
})();
Output: Total estimated Gas Fee: 1050780143553
Gas Estimate: {
success: true,
estimatedGas: BigNumber { _hex: '0xf4a7608fc1', _isBigNumber: true }
}`.

But when user call a specific contract method (mint NFT), the getEstimateGas will meet error:

Cotract address: https://explorer.testnet.mantle.xyz/address/0xF0681C0ae6eA87dbF8D7D2fe56d81D05C7f4eCa6/contracts#address-tabs

Script that cause error:
`const Web3 = require("web3");
const web3 = new Web3(new Web3.providers.HttpProvider("https://rpc.testnet.mantle.xyz"));
var fs = require('fs');
const { sleep } = require('./sleep.helper.js');
const { getEstimateGas } = require("./estimateGas.helper.js");
require('dotenv').config();

var contract_address = process.env.CONTRACT_ADDRESS;
var contract_jsonFile = "./fan_card_abi.json";
var contract_parsed = JSON.parse(fs.readFileSync(contract_jsonFile));
var contract_abi = contract_parsed.abi;
var contract_router = new web3.eth.Contract(contract_abi, web3.utils.toChecksumAddress(contract_address));

const walletGeneration = async () => {

const privateKey = "";
const publicKey = "";
const gasPrice = await web3.eth.getGasPrice();
try {
    var gas_balance = await web3.eth.getBalance(publicKey) / (10 ** 18);
    console.log("gas_balance", gas_balance)

    const messageHash = web3.utils.soliditySha3({ t: 'address', v: publicKey }); // userAddress is the address of the user you're whitelisting
    const signature = signerAccount.sign(messageHash).signature;

    // const expectedGas = await contract_router.methods.mintNFT(signature).estimateGas({ from: publicKey });
    const tx = await contract_router.methods.mintNFT(signature);
    const _data = tx.encodeABI();

    const pureTx = {
        to: web3.utils.toChecksumAddress(contract_address),
        data: _data,
    }

    const estimatedGasData = await getEstimateGas(pureTx);
    if (estimatedGasData.success) {
        console.log("Estimated Gas Fee ", estimatedGasData.estimatedGas)
        const signedTx = await web3.eth.accounts.signTransaction(
            {
                to: web3.utils.toChecksumAddress(contract_address),
                data: _data,
                gasLimit: parseInt(estimatedGasData.estimatedGas * 2),
                gasPrice: parseInt(estimatedGasData.estimatedGas),
            },
            privateKey,
        );

        const transaction = await web3.eth.sendSignedTransaction(signedTx.rawTransaction);
        const hash = await transaction.transactionHash;
        console.log("NFT Mint Transaction Success", hash);
    } else {
        console.log("Error ocurred to get estimated gas")
    }
} catch (error) {
    console.log("Error ", error);
}

}

walletGeneration();`

Error looks like:
Error estimating gas: Error: cannot estimate gas; transaction may fail or may require manual gas limit [ See: https://links.ethers.org/v5-errors-UNPREDICTABLE_GAS_LIMIT ] (reason="execution reverted: Invalid signature", method="estimateGas", transaction={"to":"0xF0681C0ae6eA87dbF8D7D2fe56d81D05C7f4eCa6","data":"0x52c253c0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000419c745e4f1316fea37908c08e2f77c5efff909c4eddca4164138519fc619cfea06e6214eb8215ad583d1d7ca1db0cb732d8c2238a21e2875869c2e81bcef064661c00000000000000000000000000000000000000000000000000000000000000","accessList":null}, error={"reason":"processing response error","code":"SERVER_ERROR","body":"{\"jsonrpc\":\"2.0\",\"error\":{\"code\":3,\"message\":\"execution reverted: Invalid signature\",\"data\":\"0x08c379a000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000011496e76616c6964207369676e6174757265000000000000000000000000000000\"},\"id\":52}\n","error":{"code":3,"data":"0x08c379a000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000011496e76616c6964207369676e6174757265000000000000000000000000000000"},"requestBody":"{\"method\":\"eth_estimateGas\",\"params\":[{\"to\":\"0xf0681c0ae6ea87dbf8d7d2fe56d81d05c7f4eca6\",\"data\":\"0x52c253c0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000419c745e4f1316fea37908c08e2f77c5efff909c4eddca4164138519fc619cfea06e6214eb8215ad583d1d7ca1db0cb732d8c2238a21e2875869c2e81bcef064661c00000000000000000000000000000000000000000000000000000000000000\"}],\"id\":52,\"jsonrpc\":\"2.0\"}","requestMethod":"POST","url":"https://rpc.testnet.mantle.xyz"}, code=UNPREDICTABLE_GAS_LIMIT, version=providers/5.7.2) at Logger.makeError (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/logger/lib/index.js:238:21) at Logger.throwError (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/logger/lib/index.js:247:20) at checkError (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/providers/lib/json-rpc-provider.js:122:20) at JsonRpcProvider.<anonymous> (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/providers/lib/json-rpc-provider.js:751:47) at step (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/providers/lib/json-rpc-provider.js:48:23) at Object.throw (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/providers/lib/json-rpc-provider.js:29:53) at rejected (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/providers/lib/json-rpc-provider.js:21:65) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) { reason: 'execution reverted: Invalid signature', code: 'UNPREDICTABLE_GAS_LIMIT', method: 'estimateGas', transaction: { to: '0xF0681C0ae6eA87dbF8D7D2fe56d81D05C7f4eCa6', data: '0x52c253c0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000419c745e4f1316fea37908c08e2f77c5efff909c4eddca4164138519fc619cfea06e6214eb8215ad583d1d7ca1db0cb732d8c2238a21e2875869c2e81bcef064661c00000000000000000000000000000000000000000000000000000000000000', accessList: null }, error: Error: processing response error (body="{\"jsonrpc\":\"2.0\",\"error\":{\"code\":3,\"message\":\"execution reverted: Invalid signature\",\"data\":\"0x08c379a000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000011496e76616c6964207369676e6174757265000000000000000000000000000000\"},\"id\":52}\n", error={"code":3,"data":"0x08c379a000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000011496e76616c6964207369676e6174757265000000000000000000000000000000"}, requestBody="{\"method\":\"eth_estimateGas\",\"params\":[{\"to\":\"0xf0681c0ae6ea87dbf8d7d2fe56d81d05c7f4eca6\",\"data\":\"0x52c253c0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000419c745e4f1316fea37908c08e2f77c5efff909c4eddca4164138519fc619cfea06e6214eb8215ad583d1d7ca1db0cb732d8c2238a21e2875869c2e81bcef064661c00000000000000000000000000000000000000000000000000000000000000\"}],\"id\":52,\"jsonrpc\":\"2.0\"}", requestMethod="POST", url="https://rpc.testnet.mantle.xyz", code=SERVER_ERROR, version=web/5.7.1) at Logger.makeError (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/logger/lib/index.js:238:21) at Logger.throwError (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/logger/lib/index.js:247:20) at /Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/web/lib/index.js:313:32 at step (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/web/lib/index.js:33:23) at Object.next (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/web/lib/index.js:14:53) at fulfilled (/Users/boreaswu/Desktop/Crypto/FT_alpha/Axelar_bridge/node_modules/@ethersproject/web/lib/index.js:5:58) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) { reason: 'processing response error', code: 'SERVER_ERROR', body: '{"jsonrpc":"2.0","error":{"code":3,"message":"execution reverted: Invalid signature","data":"0x08c379a000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000011496e76616c6964207369676e6174757265000000000000000000000000000000"},"id":52}\n',

You can use publickey: 0xdEc3262D5EADbbD946AdbB48a2A07ABe15B0AB83 and singature: 0x9c745e4f1316fea37908c08e2f77c5efff909c4eddca4164138519fc619cfea06e6214eb8215ad583d1d7ca1db0cb732d8c2238a21e2875869c2e81bcef064661c when reproduce the error.

I guess probably something wrong with the singature or the mintNFT method in their contract!

Reproduce the failure against https://rpc.testnet.mantle.xyz using the supplied public key, signature, and mintNFT calldata. Start by comparing the mintNFT ABI in fan_card_abi.json with the signature construction and the gas-estimation path in estimateGas.helper.js. Done means identifying whether the invalid signature comes from the caller data or the contract method and recording a verified resolution.