How to implement app subscriptions for multiple store types?
For example, if a user has Shopify and Bigcommerce shops in their account.
1. Can I use Shopify Billing API for Shopify shop and Bigcommerce Billing API for Bigcommerce shop for one user account?
2. Can I use Shopify Billing API to register an app subscription for a Shopify store and charge a fee for using the Bigcommerce store and vice versa?