https://appleinsider.com/articles/20/07/16/how-to-turn-automatic-ios-update-downloads-on-or-off

Note this is for system updates which is separate to app updates.

Just remember to set a reminder in your calendar to switch it back on after all of this blows over, maybe after 20-30 days (make sure you check that it's safe to do so without losing Emergency Broadcast System access).