I'm trying this code on Ropsten, it but keeps failing: contract_instance = w3.eth.contract(address="0xC36442b4a4522E871399CD717aBDD847Ab11FE88", abi=liq_ABI) tx_hash = contract_instance.functions.mint( ( '0x31F42841c2db5173425b5223809CF3A38FEde360', '0xc778417E063141139Fce010982780140Aa0cD5Ab', 3000, 49548, 50549, w3.toWei(0.001,'ether'), w3.toWei(0.17,'ether'), w3.toWei(0,'ether'), w3.toWei(0,'ether'), wallet_address, round(time.time()) + 60*20, ) ).buildTransaction({ 'from': wallet_address, 'chainId': 3, 'gas': 300000, 'gasPrice': w3.toWei(500, 'gwei'), 'nonce': w3.eth.getTransactionCount(wallet_address), 'value': Web3.toWei(0, 'ether') }) print(tx_hash) signed_tx = w3.eth.account.signTransaction(tx_hash, private_key=wallet_key) tx = w3.eth.sendRawTransaction(signed_tx.rawTransaction) Failed transaction: https://ropsten.etherscan.io/tx/0xc2f3d6ffff164df331dd4b46fc65dadc5dba8f135f6e13ef1cd383a73a2d0c4b Continue reading...