JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="txtLoginName" value="test"/>

<button id="loginBtn">Login</button>

JavaScript

$('#loginBtn').on('click',function(){
    var val = $('#txtLoginName').val();
    $('#txtLoginName').val('');
    $('#txtLoginName').val(val);
    $('#txtLoginName').focus();
   
});