Before publishing a paywall, check that you respect the following rules :
You must be transparent about your offer and not mislead users about your subscription or the services you offer.
You must clearly display information about the price that will be charged and the length of the renewal term.
Every content or feature described in this section must be available with your subscription and should get immediately unlocked once the user has subscribed.
You must not include links out of the app with purchasing opportunities or have any communication that either encourage the use of other purchasing methods or discourage the use of in-app purchase.
You cannot monetize built-in capabilities provided by the hardware or operating system (push notifications, air-play, use of camera etc...).