The code will make second passwords field's text red until the password matched

password_check.js

//Change id with your password field's id

let passwordOne = document.getElementById("ff_143_password");
let passwordTwo = document.getElementById("ff_143_password_again");

passwordTwo.addEventListener('keyup', function(){
  let passwordTwo = document.getElementById("ff_143_password_again");
  console.log(passwordTwo.value);
  //code here
  if(passwordTwo.value==passwordOne.value){
      passwordTwo.style.color = 'blue';
  }else{
      passwordTwo.style.color = 'red';
  }
});