How to create a show/hide button for sidebar using toggle?

Site URL: https://www.elizabeth-pierce.com/meal-plan-app

Hi all,

I've created a sidebar using a plugin and I'm looking for a way to be able to show or hide it upon clicking a button.

I found a way to show more or less using code I found on this forum, however, because my sidebar was created using a separate page, the show more/show less buttons only work for the 'sidebar' page and not the 'meal plan app.' page it was made for.

Here is the code I tried (from this thread: https://forum.squarespace.com/topic/49530-how-do-i-create-hideshow-section-of-an-entire-page-of-text-images-and-or-galleries-in-squarespace-spoiler-functionaccordiancollapse/):

<script>
 /* This script is a custom script to control the 'show' / 'hide' extra feature.  
 To use: give each button you want to make an expander an href of "expand-3", if you want it to expand / collapse the next 3 blocks.

 Make sure to make each button say 'Show More' as its default text.
 */

 var SHOW_MORE = 'Show More'
 var COLLAPSE = 'Show Less'
 $(window).load(function(){
   // prepares all buttons by wrapping the correct # of following divs into a div with class 'extra_gallery'
   $('a[href^="#expand"]').each(function(){
     // parse # of sibling elements to wrap from href attribute and then wrap them.
     var n = parseInt($(this).attr('href').split('-')[1]);
     var next_n_divs = $(this).parents('div.sqs-block').nextAll().slice(0,n)
     // this is the line that is different.  we use display:none; on the DOM element that wraps the additional gallery.
     next_n_divs.wrapAll('<div class="extra-gallery" style="display:none;"></div>');
/*      // preload_images
     next_n_divs.find('img').each(function(){
       image = new Image();
       image.src = $(this).attr('data-src')+'?format=500w';
       console.log($(this).attr('data-src'));
     });
     // control for click behavior
     */
     $(this).click(function(){
       var target_gallery = $(this).parents('div.sqs-block').next('div.extra-gallery')
       if (target_gallery.is(':visible')){
         $(this).text(SHOW_MORE);
       }
       else {
         $(this).text(COLLAPSE);
       }
       target_gallery.slideToggle();
       return false;
     });
   });
 });
</script>