To find In-App purchases within the free application, launch Calendars and either tap on the More button on the upper toolbar or create an event and tap on the green More button.
Note: To reveal the More button on iPhone, tap on the three horizontal lines button .
Below you can check the list of In-App Purchases:
Note: Due to the restrictions of the Family Sharing feature, any In-App Purchases made in the free version of the Calendars will not be available through the Family Sharing. You need to buy Calendars 5 to share it with other members of your household.