javascript not working in rails code example

Example: javascript not working on rails app

//= Add the following to your app/assets/javascripts/application.js file

$(document).ready(

  function(){
	
    	<add custom javascript here>
    
  }
)

//= also make sure you have the following at the top of your .js file:

//= require rails-ujs
//= require activestorage
//= require_tree .
//= require jquery
//= require jquery_ujs
//= require_self