If your mobile screen isn't rotating, ensure to check whether if your phone screen rotation feature is enabled.

For Android Devices

1. Open your device's Settings app.
2. Tap Accessibility.
3. Tap the Auto-rotate screen.

For Specific Device such as Samsung

1. If you are using Samsung, Swipe down from the top of the screen to reveal the notification panel.

2. Tap Auto-rotate

3. To return to the auto-rotation setting, tap the Lock icon to lock screen orientation (e.g. Portrait, Landscape).

For iPhone Device

For iPad Device

1. Make sure that Rotation Lock is off: Swipe down from the top-right corner of your screen to open Control Center. Then tap the Rotation Lock button

to make sure it's off.

2. Turn your iPad sideways.

If the screen still doesn't rotate, try a different app like Safari or Messages, which work in landscape mode, and check to see if your iPad has a side switch.

If you don't see the Rotation Lock button, check to see if your iPad has a side switch. If you have an older iPad with a side switch, you can set the side switch to work as a rotation lock or mute switch.

Go to Settings > General. Under Use Side Switch To, select the option that you want.

Remember that not all apps support rotation. If some apps on your iPad rotate as expected and others don't rotate, the ones that don't were built that way by their developers.