resolve missing provider error in ethrDid.setAttribute

[humuhimi]

Description of Changes

In the EthrDID class constructor, when the following code executes:

if (conf.privateKey && typeof txSigner === 'undefined') {
    txSigner = new Wallet(conf.privateKey);
}

it causes an error if no provider is set. The issue occurs in node_modules\ethers\src.ts\providers\abstract-signer.ts at:

function checkProvider(signer: AbstractSigner, operation: string): Provider {
    if (signer.provider) { return signer.provider; }
    assert(false, "missing provider", "UNSUPPORTED_OPERATION", { operation });
}

Error Message:

Error: missing provider (operation="sendTransaction", code=UNSUPPORTED_OPERATION, version=abstract-signer/5.5.0)
reason: 'missing provider',
code: 'UNSUPPORTED_OPERATION',
operation: 'sendTransaction'

Fix:

The issue was resolved by modifying the txSigner initialization to include the provider:

txSigner = new Wallet(conf.privateKey, conf.provider || conf.web3?.currentProvider);

Related Issue

#81

This ensures a valid provider is passed, preventing the error.