Basic menu mobile

First, you need to load the jQuery library:

<script src="https://code.jquery.com/jquery-3.6.1.js"></script>

After that, add the jQuery function:

<script>

    $(document).ready(function(){

        $(".hamburger").on("click",function(){
            $(".main-header").addClass("menu-open");
        });
        $(".close-hamburger").on("click",function(){
            $(".main-header").removeClass("menu-open");
        });

    });

</script>