JSFiddle - React, Tailwind, and code Playground

HTML

<input id="text_box_url" type="text"/>

JavaScript

$(document).ready(function() {
  $("#text_box_url").blur(function() {
    var input = $(this);
    var val = input.val();
 
    if (val.match(/^.+:\/\/.*/)) {
        alert('yes');
    }
  });
});