Need to use jquery to use .click().

js/lb-direct-add.js

@@ -31,7 +31,7 @@
       var $directAddWidgets = once('.layout-builder__add-block', 'lb_direct_add', context);
 
       if ($directAddWidgets.length) {
-        var $body = once('body', 'lb_direct_add-click', context);
+        var $body = $(once('body', 'lb_direct_add-click', context));
 
         if ($body.length) {
           $body.on('click', '.layout-builder__direct-add__toggle', directAddClickHandler);