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).
Trump will not use the EBS and Apple is not removing it in their latest update.