UpCart supports HTML, CSS, and JavaScript code for customizations.
This means you can create things, make things look pretty, and make things happen too!
The video below is an overview of how you can get started with customizing your UpCart.
Support for Customizations
UpCart's support team is not able to help you implement custom solutions into your cart. If you'd like help building something custom, we suggest consulting with a Shopify Expert here: https://www.shopify.com/partners/directory