JSFiddle - React, Tailwind, and code Playground

HTML

<form name="form" onsubmit="return validate();" method="get">
   <div class="form-group">
      <label for="pass">Password</label>
      <input type="password" class="form-control" name="pass" id="pass">
   </div>
   <div class="form-group">
      <label for="pass2">Re-Type Password</label>
      <input type="password" class="form-control" name="pass2" id="pas2">
   </div>
</form>

JavaScript

const arrayElement = document.querySelectorAll('.form-group');

for(let i = 0; i < arrayElement.length; i++)
{
  const errorMessage = document.createElement('span');
  errorMessage.textContent = "invalid input";
  arrayElement[i].appendChild(errorMessage);
}