JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    Username: <input type="text" name="user" id="user"/><br>
    Password: <input type="passWORD" name="pass" id="pass"/>

JavaScript

var saveoption=true;
if(saveoption==true)
{
    var saveduser="piyushkmr"; //get username from javascript cookies or PHP
}

$(window).ready(function(){
    if(saveduser!="")
    {
        $("#user").val(saveduser);
        
    }
    
});