How can I add donation campaigns to my checkout process?

[bilal87]

I am creating a shopify app to add campaigns to add donations for the shopify products or the whole orders.

I have been searching over the Internet and not much information is provided I am confused how I can modify the cart page of shopify through the app as the asset api is limited now starting 2023 and 2024.

How can I modify one other option is to add theme app extension I am still confused which is the best route how can I add donations with specific campaigns.