Add sign-and-send code to the operations.js

operations.js

/**
 * Transfer token from one to another.
 * @param {String} addressContract Contract address.
 * @param {String} signerAddress Enforce who signs the transaction.
 * @param {String} toAddress Receiver of transfer.
 * @param {String} amountEVM Big number in string.
 * @param {Number} amountHuman Normal number in Javascript.
 * @param {String} symbol Symbol of token.
 */
async function transferToken (addressContract, signerAddress, toAddress, amountEVM, amountHuman, symbol) {
    const transferABI = {
      'constant': false,
      'inputs': [
        {
          'name': '_to',
          'type': 'address'
        },
        {
          'name': '_value',
          'type': 'uint256'
        }
      ],
      'name': 'transfer',
      'outputs': [
        {
          'name': '',
          'type': 'bool'
        }
      ],
      'payable': false,
      'stateMutability': 'nonpayable',
      'type': 'function'
    }
    // eslint-disable-next-line
    const transferMethod = connex.thor.account(addressContract).method(transferABI)
    const transferClause = transferMethod.asClause(toAddress, amountEVM)
    // eslint-disable-next-line
    const signingService = connex.vendor.sign('tx')
    signingService
      .signer(signerAddress) // Enforce signer
      .comment('Token transfer: ' + amountHuman.toString() + ' ' + symbol)
  
    let transactionInfo = await signingService.request([
      {
        comment: 'Hello! Transfer Demo!',
        ...transferClause
      }
    ])
    return transactionInfo
  }