Shopify App

[NagendraRV]

Hi, I am working on a project where we are fetching orders from a merchant's Store. I am getting confused about creating Shopify App. I am using Laravel.
Our Shopify App is free to use but our portal subscriptions are chargeable.

Okay, so this is my current scenario.

I have a different table for the shop name shops and one more table called user_shops where I am storing the ids of shops and users.
Now comes to Billing API, I am getting confused. We also have free subscriptions too.
So, how can I handle billing API?

Thank you!