Can I create a way to unlock an entitlement outside of an In-App Purchase?

Would it be possible to create a section in my app, where the users can enter a custom code which will unlock a certain entitlement?

Unfortunately this it’s against App Store rules to have a promo code redemption form like this unless you sell physical goods (in which case you can’t use in-app purchases anyway.) 

On the app store, I can create a promo code that grants a 1 year free trial, but this will auto renew on the individual users Apple ID’s, which is not what I want.

RevenueCat does offer a feature called Promotional Subscriptions (API documentation here) that you can use to grant a user a specific duration of an entitlement in RevenueCat without needing to go through any purchases or payment flows. But RevenueCat doesn’t collect money or offer any sort of promo code system, so you will have to collect that one-time payment some other way and track which employees are included in the partnership, potentially outside of the iOS app. Then you can use RevenueCat’s API to give users access to the entitlement. 

Yes, in lots of ways. 

It is against ToS. 

You could make an endpoint, tag a group of users, identify them, then entitle them via API by sending packets to the endpoint. 

RC entitlements can be applied via webhook you would just need some kind of marker in-app to do so .

Promo codes are against Apple ToS (working around the app store purchase is a no-no) but granting special permissions or features based on purchases out of the app opn a different platform are allowed. 

Just not via promo codes or user-entered/triggered events. You just need a way to identofy these users in app? 

Firebase remote config white list by email?