i'm using metamask with ropsten. deployed my contract on ropsten using remix. for the backend i used infura to create instance of web3. ew Web3(new Web3.providers.HttpProvider('https://ropsten.infura.io/v3/MY_API_KEY'));
i'm able to get data from blockchain by contract.getDetails(123); but while sending the details i'm getting below error, "The method eth_sendTransaction does not exist/is not available"
I understand you problem, this is due to API version change between Infura and Web3. Please try to match the version of Web3 API with Infura.
Install and use truffle-hdwallet-provider to create a provider using your mnemonic and the infura endpoint. You can then pass this provider while creating instance of Web3:
const HDWalletProvider = require("truffle-hdwallet-provider"); const provider = new HDWalletProvider( mnemonic, 'https://ropsten.infura.io/v3/MY_API_KEY' ); const web3 = new Web3(provider); 