Steps failed

### Description

Using node 20

I followed the steps including setting the env variable, but the `hardhat test` command failed.

```
$ npx hardhat test
You are using a version of Node.js that is not supported by Hardhat, and it may work incorrectly, or not work at all.

Please, make sure you are using a supported version of Node.js.

To learn more about which versions of Node.js are supported go to https://hardhat.org/nodejs-versions
✖ Help us improve Hardhat with anonymous crash reports & basic usage data? (Y/n) · y

RPC
1) should be able to get the account balance
2) should be able to deploy a contract
3) should be able to make a contract view call
4) should be able to make a contract call

0 passing (262ms)
4 failing

1) RPC
should be able to get the account balance:
Error: could not detect network (event="noNetwork", code=NETWORK_ERROR, version=providers/5.7.2)
at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
at EthersProviderWrapper. (node_modules/@ethersproject/providers/src.ts/json-rpc-provider.ts:483:23)
at step (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:48:23)
at Object.throw (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:29:53)
at rejected (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:21:65)
at processTicksAndRejections (node:internal/process/task_queues:95:5)

2) RPC
should be able to deploy a contract:
Error: could not detect network (event="noNetwork", code=NETWORK_ERROR, version=providers/5.7.2)
at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
at EthersProviderWrapper. (node_modules/@ethersproject/providers/src.ts/json-rpc-provider.ts:483:23)
at step (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:48:23)
at Object.throw (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:29:53)
at rejected (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:21:65)
at processTicksAndRejections (node:internal/process/task_queues:95:5)

3) RPC
should be able to make a contract view call:
Error: invalid contract address or ENS name (argument="addressOrName", value=undefined, code=INVALID_ARGUMENT, version=contracts/5.7.0)
at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
at Logger.throwArgumentError (node_modules/@ethersproject/logger/src.ts/index.ts:285:21)
at Contract.BaseContract (node_modules/@ethersproject/contracts/src.ts/index.ts:712:20)
at new Contract (node_modules/@ethersproject/contracts/lib/index.js:1053:42)
at Function.ContractFactory.getContract (node_modules/@ethersproject/contracts/src.ts/index.ts:1297:16)
at ContractFactory.attach (node_modules/@ethersproject/contracts/src.ts/index.ts:1260:42)
at getContractAtFromArtifact (node_modules/@nomiclabs/hardhat-ethers/src/internal/helpers.ts:381:26)

4) RPC
should be able to make a contract call:
Error: invalid contract address or ENS name (argument="addressOrName", value=undefined, code=INVALID_ARGUMENT, version=contracts/5.7.0)
at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
at Logger.throwArgumentError (node_modules/@ethersproject/logger/src.ts/index.ts:285:21)
at Contract.BaseContract (node_modules/@ethersproject/contracts/src.ts/index.ts:712:20)
at new Contract (node_modules/@ethersproject/contracts/lib/index.js:1053:42)
at Function.ContractFactory.getContract (node_modules/@ethersproject/contracts/src.ts/index.ts:1297:16)
at ContractFactory.attach (node_modules/@ethersproject/contracts/src.ts/index.ts:1260:42)
at getContractAtFromArtifact (node_modules/@nomiclabs/hardhat-ethers/src/internal/helpers.ts:381:26)

```

Using node 18, the error still occurred but without the nodejs warning.

### Steps to reproduce

1. Follow readme instructions

### Additional context

_No response_

### Hedera network

testnet

### Version

What is "the software" in this case? I just checked out this repo.

### Operating system

Linux