JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <input type="button" id="btnCheckAll" value="Check All"/>
    <input type="button" id="btnAddNew" value="Add checkbox" >
        <br/>
	<div class="checkDiv">
        <input type="checkbox" class="chk"/>check 1
        <input type="checkbox" class="chk"/>check 2
        <input type="checkbox" class="chk"/>check 3
        <input type="checkbox" class="chk"/>check 4
	</div>
	
</body>

JavaScript

$(document).ready(function(){
    
    $("#btnCheckAll").click(function(){
     
    $(".chk").each(function(){
        $(this).prop("checked","checked");
    
    });
   
    });
    
    
      $("#btnAddNew").click(function(){
         for(var i=0;i<5;i++){
    $(".checkDiv").append("<input type='checkbox' class='chk'/>check "+i);
         }
   
    });
    	
   

});