How can I add an add-to-cart summary pop-up with upselling options?

[planetjuniorseo]

Hi, I want to add an add-to-cart summary pop-up on my site which shows the cart summary in a pop-up with upselling options just like this image.

The images are from this page: https://www.salitexonline.com/

Can anyone suggest any app to achieve this (preferably a free app)?