Does Apple allow promo codes in apps?

Question

Apple Developer Program

I want to add a system with promo codes to the game. The game has coins that can be bought with standard In-app purchases, I would like to add the input of promotional codes, for which the user can get coins for free.
Googling turned up nothing on this.
Are such promo codes prohibited by Apple rules?

Answer 1

there is an island game, so there you can either buy a game currency or enter a promotional code (it used to be like this, the promotional code appeared at a certain time on the facebook page, but now you just need to go through the facebook application) so I think that it is possible, provided that it is promo codes will not be sold.
also seems to have codes in wot blitc

Answer 2

Codes should not be sold and still depends on the moderator, it can wrap up anyway. Ideally, with a promo code, you can unlock content that is not available through the in-app or such that you can farm.