https://eips.ethereum.org/EIPS/eip-155 The The default value of chainId is 1 for ETH, You must add the correct value of chainId for POLYGON. more information: https://eips.ethereum.org/EIPS/eip-155
'to': receiver1,
'value' w3.toWei(1, eth),
'gas': 21000,
'gasPrice': w3.toWei(50, gwei),
'chainId': 137
}
tx = {'nonce': nonce,
'to': receiver1,
'value' w3.toWei(1, eth),
'gas': 21000,
'gasPrice': w3.toWei(50, gwei),
'chainId': 137
}