Implement in-app subscriptions

I am developing a mobile application using Flutter and plan to implement in-app subscriptions for both iOS platforms. I would like to request guidance on the following:

1. Technical Implementation:

   • Recommended best practices for implementing auto-renewable subscriptions in Flutter apps

   • StoreKit 2 integration requirements and compatibility considerations

   • Server-to-server notification setup and endpoint requirements

2. Testing Procedures:

   • Sandbox environment configuration and testing workflow

   • TestFlight testing requirements for subscription features

   • Recommended testing scenarios before production release

3. Required Documentation and Accounts:

   • Complete list of required agreements (Paid Applications Agreement, etc.)

   • Banking and tax information requirements

   • Privacy policy and terms of service specifications for subscription apps

   • App Review guidelines specific to subscription-based apps

4. Subscription Management:

   • Grace period implementation requirements

   • Handling subscription cancellations and refunds

   • Promotional offers and introductory pricing setup

Could you please provide documentation or direct me to the appropriate resources? Additionally, if there are any specific requirements for Flutter-based applications, I would appreciate that information.

Application Details:

• Platform: iOS (Flutter framework)

• Subscription Type: Auto-renewable subscriptions