Question: am I required to use Firebase if I need to implement in_app_purchase in my app?
The Google says to implement in app purchase, you have to use: pub.dev/packages/in_app_purchase
There is the codelab: codelabs.developers.google.com/codelabs/flutter-in-app-purchases#0
This lab shows Firebase in the pubspec file. Hence, I thought that the Firebase is required.
Can I use any database or I have to use Firebase to implement in app purchase?
Please let me know your thoughts when you get a chance.
It's pretty clear to me in the codelab itself that Firebase is not required. It's just illustrated as a convenience so the codelab won't require you to implement an entire backend in order to get it to work. From the codelab text:
While there are many ways to set up a backend service, you'll do this using cloud functions and Firestore, using Google's own Firebase.
Writing the backend is considered out of scope for this codelab, so the starter code already includes a Firebase project that handles basic purchases to get you started.
Firebase is also never mentioned in the readme for the in_app_purchase package you linked.