This article explains how to temporarily deactivate your Facebook account on iPhone. It also describes the key differences between deactivating and deleting.

In the Facebook app, you can deactivate your Facebook profile in a few simple steps. If you change your mind, you can always reactivate it later.

Launch the Facebook app and tap the three horizontal lines in the bottom right corner of the screen. The Facebook menu will appear.

Scroll down and tap Settings & privacy > Settings.