How can I dynamically change products with a checkout UI extension schema?

I’m new to app development and I have a shopify plus store.

I’m trying this ‘checkout ui extension’ app and specifically the ‘add product’ (which basically add a product in the information page and allow the customer to add in one click: https://shopify.dev/apps/checkout/product-offers/add-product-offer)..)

The issue here is that the product information are hardcoded and as you can understand not UX friendly for my team to change the product as they need.

I want to add a schema with a ‘select product’ to dynamically change it when they need.

When you pull the code ‘create @Shopify_77 /app’ there is only an index.js file and I can’t see any way to add liquid rules.

Is there a way to make this happen?

Thank you.