Finding the appropriate payment product category

I am developing an health program app, that assists the wellness of a user based on following certain instructions provided from a department. The health program is a fixed course. A user following instructions for this duration is said to have improved, if so the program is ended else the user has to restart. In order to get these instructions, the user needs to pay, either monthly or single time. once the duration is over, if the user needs to improve again then the program can be purchased again else stopped.

Based on the apple documents, I understood we need to use In-App purchasing. To which category does this payment type belongs to and is there any guidelines.

Thanks