`executeTxn` may fail

You're passing the `value` in the call taken from the input parameter, as a `uint256` instead of the `msg.value` and making the function `payable`.

This will revert if you pass a parameter greater than zero, as the transaction itself will have a `msg.value` of 0.

```solidity
function executeTxn(
uint256[2] memory a,
uint256[2][2] memory b,
uint256[2] memory c,
uint256[2] memory input,
address callee,
uint256 value
) external isOwner returns (bytes memory result) {
require(verifyOTP(a, b, c, input), "Proof failed");
(bool success, bytes memory result) = callee.call{value: value}("");
require(success, "external call reverted");
// emit TransactionExecuted(callee, value, data);
return result;
}
```

You could delete the `value` input, make the function `payable` and change
```
(bool success, bytes memory result) = callee.call{value: value}("");
```
to
```
(bool success, bytes memory result) = callee.call{value: msg.value}("");
```