Calling a contract method

[cipaterson]

Hi, I just wanted to clarify something if someone can set me right -

This:
https://docs.web3js.org/guides/smart_contracts/deploying_and_interacting_with_smart_contracts#step-7-interact-with-the-smart-contract-using-web3js
shows sending a tx to invoke a contract method:

        const receipt = await MyContract.methods.setMyNumber(myNumber + 1n).send({
            from: defaultAccount,
            gas: 1000000,
            gasPrice: 10000000000,
        });

Which works for my local node but it won't work for a remote provider like Infura or Alchemy - right?

I get an error when executing this against Infura:
InvalidResponseError: Returned error: The method eth_sendTransaction does not exist/is not available

This is because remote providers don't store private keys and so can't sign the Tx for us, we need to sign the tx locally and send with something like this:

// Issuing a transaction that calls the `echo` method
  const method_abi = contract.methods.echo("Hello, world!").encodeABI();
  const tx = {
    from: signer.address,
    to: contract.options.address,
    data: method_abi,
    value: '0',
    gasPrice: '100000000000',
  };
  const gas_estimate = await web3.eth.estimateGas(tx);
  tx.gas = gas_estimate;
  console.log(tx)
  const signedTx = await web3.eth.accounts.signTransaction(tx, signer.privateKey);

Am I right or can web3.js understand that it's not dealing with a local node and can the .send() do the signing for me?