appending to non existance selector

appending to non existance selector

hey guys im trying to create a selector in a foreach loop and append to it further down in my code

what is the best way to achive this please?

  1.   $.each(data, function(category, stuff) {
         
                $("#categories").append('<li id="category_'+ category +'">' + category + '</li>');
           
            $.each(stuff, function(sub_category, items){
                // $('category_' + category).append('<li id="sub_category_'+ sub_category +'">' + sub_category + '</li>');  // here is the error.
        
            });
        });

thank you