This violates the App Store Review Guidelines 3.1.3(b) [1]:
> You must not directly or indirectly target iOS users to use a purchasing method other than in-app purchase, and your general communications about other purchasing methods must not discourage use of in-app purchase.
> You must not directly or indirectly target iOS users to use a purchasing method other than in-app purchase, and your general communications about other purchasing methods must not discourage use of in-app purchase.
[1]: https://developer.apple.com/app-store/review/guidelines/#mul...