Call contract methods with web3 from newly created account - ethereum

Question

I need to call methods from my contract in Ethereum without using MetaMask. I use Infura API and try to call my methods from account, recently created with web3.eth.create() method. This method returns object like this:
{
address: "0xb8CE9ab6943e0eCED004cG5834Hfn7d",
privateKey: "0x348ce564d427a3311b6536bbcff9390d69395b06ed6",
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
I also using infura provider:
const web3 = new Web3(new Web3.providers.HttpProvider(
"https://rinkeby.infura.io/5555666777888"
))
So, when I try to write smth like that:
contract.methods.contribute().send({
from: '0xb8CE9ab6943e0eCED004cG5834Hfn7d', // here I paste recently created address
value: web3.utils.toWei("0.5", "ether")
});
I have this error:
Error: No "from" address specified in neither the given options, nor
the default options.
How it could be no from address if I write it in from option??
P.S. With Metamask my application works fine. But when I logout from MetaMask and try to create new account and use it, I have that issue.

Answer 1

In fact, we can't just send transactions from newly created address. We must sign this transaction with our private key. For example, we can use ethereumjs-tx module for NodeJS.
const Web3 = require('web3')
const Tx = require('ethereumjs-tx')
let web3 = new Web3(
new Web3.providers.HttpProvider(
"https://ropsten.infura.io/---your api key-----"
)
)
const account = '0x46fC1600b1869b3b4F9097185...'; //Your account address
const privateKey = Buffer.from('6e4702be2aa6b2c96ca22df40a004c2c944...', 'hex');
const contractAddress = '0x2b622616e3f338266a4becb32...'; // Deployed manually
const abi = [Your ABI from contract]
const contract = new web3.eth.Contract(abi, contractAddress, {
from: account,
gasLimit: 3000000,
});
const contractFunction = contract.methods.createCampaign(0.1); // Here you can call your contract functions
const functionAbi = contractFunction.encodeABI();
let estimatedGas;
let nonce;
console.log("Getting gas estimate");
contractFunction.estimateGas({from: account}).then((gasAmount) => {
estimatedGas = gasAmount.toString(16);
console.log("Estimated gas: " + estimatedGas);
web3.eth.getTransactionCount(account).then(_nonce => {
nonce = _nonce.toString(16);
console.log("Nonce: " + nonce);
const txParams = {
gasPrice: 100000,
gasLimit: 3000000,
to: contractAddress,
data: functionAbi,
from: account,
nonce: '0x' + nonce
};
const tx = new Tx(txParams);
tx.sign(privateKey); // Transaction Signing here
const serializedTx = tx.serialize();
web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex')).on('receipt', receipt => {
console.log(receipt);
})
});
});
Transaction time is about 20-30 seconds so you should wait quite a bit.