External purchase links vs IAP

We have live App Store app and one of the use case is that, Users buy on our web via Stripe, can access content (Zoom, recordings, PDFs). We are considering, In-app payment for Education Groups ($469, one-to-many live coaching) and access to content in the app . Q1: Can we include a button that opens our web checkout? If yes, which is allowed: (a) Opens inside the app (in-app browser / SFSafariViewController / WKWebView) — user stays in app? (b) Opens outside the app (Safari) — user leaves the app?

US users: which is allowed under 3.1.1(a)? Non-US users: which is allowed (with StoreKit External Purchase Link Entitlement)?

Q2: For our one-to-many service, 3.1.3(d) states "must use IAP" but 3.1.1(a) allows external options in US.

US users: Can we offer external only, or is IAP required alongside? Non-US users: Is IAP mandatory, or are there exceptions for live group coaching?

External purchase links vs IAP
 
 
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