Apple allowed apps to use alternate payment methods for in-app group events as an exception for some time (in contract with one-on-one events which could use alternate payments). Deadline for switching back to in-app purchases was extended several times, but as of now Apple sets deadline to December 31, 2021.
Starting January 1, 2022 apps must use in-app purchase mechanism for group events.
As a reminder, new apps and updates offering these realtime one-to-few and one-to-many services must use in-app purchase by December 31, 2021, or they won’t be approved per guideline 3.1.1. Apps offering realtime person-to-person services between two individuals (for example, tutoring students, medical consultations, real estate tours, or fitness training) can continue using purchase methods other than in-app purchase.Apple Developer
Apple Developer: Online group event in-app purchase requirement reminder
Developer:Business as usual.
QA engineer:Business as usual.
PM/DM:Switch payments for group events to in-app purchases.