unable to send a signed transaction

[mabdullahh]

I am unable to send a signed transaction. Using infura network. Have a look at my code and error.

//building the transaction
_txn = await Transaction(
from: EthereumAddress.fromHex('$_ownAddress'),
to: EthereumAddress.fromHex('$_contractAddress'),
gasPrice: EtherAmount.inWei(BigInt.one),
value: EtherAmount.fromUnitAndValue(EtherUnit.wei, 1000),
maxGas: 100000,
nonce: 17,
);
//signing the transaction
_signedtxn = await _client.signTransaction(_credentials, _txn);
print('Signed transaction : $_signedtxn');
// sending signed transaction
_sendSigned = _client.sendTransaction(_credentials, _txn);

[simolus3]

Can you try setting the chain id?