The Flight Crew View app does not create alerts or alarms with each event that it creates. The notifications for those events are managed and created by the Device Calendar app itself.
To update those settings, you will need to update those settings in your Device Calendar app.
If you want to keep notifications for all of your other events, though, and just disable the Flight Crew View notifications, you may have to create a new Calendar just for the Flight Crew View events and then manage the notifications for specifically that calendar.
If you still have questions, please send us an email to firstname.lastname@example.org