Hello,
You can show the upsells products in the sidebar like your example site. Navigate to Theme Settings > Single Product > Related & Upsells > Upsells products position > Choose sidebar.
If you want to show the frequently bought together in the sidebar area. You can use the Theme’s Layout Builder to create Custom Layouts for the Single Product page > and in that Layout you can change or configure the elements accordingly. You can add the Frequently bought tother widget in the layout: You can find the Layouts under the Dashboard > Layouts.
Here is the Guide to that: https://xtemos.com/docs-topic/single-product-page-builder/
Best Regards.
.
