Use AssistiveTouch on your iPhone, iPad, or iPod touch - Apple Support --> Use AssistiveTouch on your iPhone, iPad, or iPod touch - Apple Support
You can use AssistiveTouch to adjust volume, lock your screen, use multi-finger gestures, restart your device, or replace pressing buttons with just a tap.
When you turn on AssistiveTouch, you’ll see the AssistiveTouch menu. You can drag it to any edge of the screen, then tap the menu to open it.
I don't know the details of using it in your particular case but you can read the article for more information.