Is this the correct way to add string extra string data to a solidity contract

Question

This is my first solidity contract, it was working until I wanted to add extra data to the transaction. I'm not sure if I'm calling it wrong with webjs3 or the contract itself is flawed in some way.

pragma solidity ^0.8.0;

// SPDX-License-Identifier: MIT

contract PaymentSplitter {
    address public owner;
    address payable public payee1;
    address payable public payee2;
    string public storedString;

    constructor(address payable _payee1, address payable _payee2) {
        owner = msg.sender;
        payee1 = _payee1;
        payee2 = _payee2;
    }

    receive() external payable {
        uint256 totalReceived = msg.value;

        uint256 amountToPayee1 = (totalReceived * 90) / 100;
        uint256 amountToPayee2 = (totalReceived * 10) / 100;

        // Send Ether to payee1
        payee1.transfer(amountToPayee1);

        // Send Ether to payee2
        payee2.transfer(amountToPayee2);
    }

    event StringProcessed(address indexed sender, string data);

    function processStringData(string calldata data) external {
        emit StringProcessed(msg.sender, data);
        storedString = data;
    }
}

webjs

 const contractAddress = '0x9b8b9D5Ee2337e0F9D4Dd4c7f8b5bF008e9de3f5';
          const contractABI = [{ "inputs": [{ "internalType": "string", "name": "data", "type": "string" }], "name": "processStringData", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [{ "internalType": "addresspayable", "name": "_payee1", "type": "address" }, { "internalType": "addresspayable", "name": "_payee2", "type": "address" }], "stateMutability": "nonpayable", "type": "constructor" }, { "anonymous": false, "inputs": [{ "indexed": true, "internalType": "address", "name": "sender", "type": "address" }, { "indexed": false, "internalType": "string", "name": "data", "type": "string" }], "name": "StringProcessed", "type": "event" }, { "stateMutability": "payable", "type": "receive" }, { "inputs": [], "name": "owner", "outputs": [{ "internalType": "address", "name": "", "type": "address" }], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "payee1", "outputs": [{ "internalType": "addresspayable", "name": "", "type": "address" }], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "payee2", "outputs": [{ "internalType": "addresspayable", "name": "", "type": "address" }], "stateMutability": "view", "type": "function" }, { "inputs": [], "name": "storedString", "outputs": [{ "internalType": "string", "name": "", "type": "string" }], "stateMutability": "view", "type": "function" }];
          const contract = await new web3.eth.Contract(contractABI, contractAddress);

          const fromAddress = accounts[0];
          const stringData = checkoutDetails; // Replace with your string data
          const data = web3.utils.utf8ToHex(stringData);
          const valueInWei = web3.utils.toWei('1', 'ether');

          // Construct the data field by prepending the function selector (4 bytes)
          const functionSelector = web3.eth.abi.encodeFunctionSignature('processStringData(string)');
          const txData = functionSelector + data.slice(2);

          // Create a transaction object with the properly formatted data
          const tx = {
            from: fromAddress,
            to: contractAddress,
            value: valueInWei,
            data: txData,
          };

          web3.eth.sendTransaction(tx)
            .then(receipt => {
              console.log('Transaction Receipt:', receipt);
            })
            .catch(error => {
              console.error('Error:', error);
            });

Any guidance is appreciated