JSFiddle - React, Tailwind, and code Playground

HTML

<form id="firstForm">
    <h3>Form 1</h3>
    <input type="text" name="name">
    <input type="submit" value="submit">
</form>

<form id="secondForm">
    <h3>Form 2</h3>
    <input type="text" disabled>
    <input type="submit" value="submit" disabled>
</form>

JavaScript

$('#firstForm').submit(function(e){
    e.preventDefault();
    
    $.ajax({
        method: 'POST',
        url: "/echo/json/",
        success: function(){
           $('#secondForm').children().attr('disabled', false);
        }
    });
});