My iPhone won’t rotate

The easiest answer is to just turn the iPhone. What will prevent it from happening is if you have the Rotation Lock set to ON. Check for this setting in the control center. SWIPE UP from the bottom and reveal the control center. Ensure that the Screen Rotation Lock button is NOT highlighted.

One other thing that you should note is that the iPhone is not going to rotate everything that is displayed on the screen every single time. What rotates and what does not rotate is decided by the app that is in use.

Axel F.