Using 3 and 4 finger gesture

Turn on AssistiveTouch

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. 

There are a few ways to turn on AssistiveTouch:

• Go to Settings > General > Accessibility > AssistiveTouch, then turn on AssistiveTouch.
• Tell Siri “Turn on AssistiveTouch.” 
• Go to Settings > General > Accessibility > Accessibility Shortcut and turn on AssistiveTouch. 

Use gestures

On your iPhone X or later you can use gestures to quickly navigate, multitask, adjust settings, and access all the things you do the most.

Swipe or drag with multiple fingers:

1. Open the AssistiveTouch menu and tap Device > More > Gestures. 
2. Select the number of fingers associated with the gesture you want to make.
3. When the circles appear, swipe or drag in the direction required by the gesture.
4. When you finish, tap the menu button.

Pinch:

1. Open the AssistiveTouch menu and tap Favorites > Pinch.
2. When the pinch circles appear, move them anywhere on the screen. 
3. Drag the pinch circles in or out.
4. When you finish, tap the menu button. 

Create your own gesture using either of these ways:

• Open the AssistiveTouch menu. Tap Custom, then select an empty gesture placeholder  . 
• Go to Settings > General > Accessibility > AssistiveTouch > Create New Gesture. Then follow the onscreen steps.

Use AssistiveTouch on your iPhone, iPad, or iPod touch - Apple Support

https://support.apple.com/en-us/HT202658