How do I access the product_form_id from app-embed.liquid?

[ericute]

Hi, everyone.

We've recently updated to use Theme App Extensions.

I'm trying to include the form object with the value of product_form_id in my app-embed.liquid file. However, when I try to deploy it, I'm getting the error below. It doesn't have access to the product_form_id. 

When we're still using the Asset API, we added this as a custom liquid file that gets rendered together with the main liquid file. (Example: main-product.liquid).

How do I retrieve it from app-embed.liquid?