transfer method
Implementation
Future<String> transfer(String receiverAddress, int amountInWei, String privateKey) async {
print('transfer start --> receiver: $receiverAddress, amountInWei: $amountInWei');
/// todo: check approved
EthereumAddress receiver = EthereumAddress.fromHex(receiverAddress);
EtherAmount amount = EtherAmount.fromUnitAndValue(EtherUnit.wei, BigInt.from(amountInWei));
///
String txHash = await _sendTransactionAndWaitForReceipt(
Transaction(to: receiver, value: amount),
privateKey,
);
print('transfer done --> txID: $txHash successful');
return txHash;
}