Apple In-App-Auto Renewal Subscription Flow Consultation Required

Submitted in-app Auto-Renewal to Apple, completed sandbox testing to process payments. Now Apple wants to include Restore options and resubmit. We have front end and backend programmers. Need to check the coding, flow check, and guide our programmers to make sure we complied with all requirements Auto-Renewal feature of Apple in order to get the approval faster. We are using Ionic-cordova platform.