We currently have an app that contains a monthly subscription to unlock the main functionality. We would like to have a way for our employees to be able to use the app without having to go through this mechanic. For instance, our sales associates and our support staff.
I had previously made a promo code field which would check the value with an API to determine whether to validate the subscription or not, but the app was denied since it didn't use the IAP system, which I understand.
I'm aware that I could somewhat achieve this behaviour through the use of promo codes, but that would require us to create a new batch of codes periodically, not to mention that every employee would need to have a payment method setup in their device, which we would like to avoid.
We could also periodically issue TestFlight builds to bypass this, but once again it's not an ideal solution since it necessitates some periodic and perpetual management.
Is there any way I can achieve this while following the App Review Guidelines?