RPCError: got code -32000 with msg "insufficient funds for transfer"

[Sahil-Kundaliya]

i have "total_balance_formatted": "0.000528902815064832",

here is code

double amount = 0.000128902815064832;
BigInt bigIntValue = BigInt.from(amount * pow(10, 18));
EtherAmount ethAmount =
EtherAmount.fromBigInt(EtherUnit.wei, bigIntValue);
var apiUrl =
"https://eth-sepolia.g.alchemy.com/v2/XXXmy_APi_KeyXXX";

      var httpClient = http.Client();
  var ethClient = Web3Client(apiUrl, httpClient);

  EthPrivateKey credentials = EthPrivateKey.fromHex('0x$XXXMy_private_KeyXXX');
  
  EtherAmount etherAmount = await ethClient.getBalance(credentials.address);
  EtherAmount gasPrice = await ethClient.getGasPrice();

  log('SSS amount is -= $etherAmount');
  print('Balance in Wei: ${etherAmount.getInWei}');
  print('Balance in Ether: ${etherAmount.getValueInUnit(EtherUnit.ether)}');
  {

this is out put why is 0.0 ??
flutter: Balance in Wei: 0
flutter: Balance in Ether: 0.0
}
await ethClient.sendTransaction(
credentials,
Transaction(
to: EthereumAddress.fromHex(XXX_receiver_XXX),
gasPrice: gasPrice,
value: txValue,
),
chainId: 11155111,
);

  {

error is => RPCError: got code -32000 with msg "insufficient funds for transfer".
}

but I have amount in wallet but it's showing 0.0 and get this error

[kevtechi]

Check here if the address of your private key has a balance: https://sepolia.etherscan.io/

With chain id 11155111, that should be sepolia.

On Sepolia, you can just get ETH from a faucet.