How to use an external mouse with your iPad
With iPadOS, you can now set up and use an external mouse with your iPad. You can use a wired mouse that connects into the Lightning or USB-C port on your tablet, or a wireless mouse that connects via Bluetooth. Once you've established the connection, you can use your mouse just as you would on a PC. Depending upon the type of work you need to do, an external mouse can be more effective and easier than using your fingers to maneuver around your iPad.
SEE: Apple iPadOS: A cheat sheet (free PDF) (TechRepublic)
First, make sure you're running iPadOS 13.1 or higher on your iPad. Then, you'll need the right type of adapter for your mouse based on your model of iPad. An iPad Pro uses a USB-C port, so you'd require a USB-A to USB-C adapter. With any other iPad, you would need a USB-A to Lightning adapter. You would use the adapter to connect a wired mouse directly or to connect the Bluetooth dongle for a wireless mouse.
Connect your mouse through the adapter to your iPad. If it's a Bluetooth mouse, make sure it's turned on. Navigate to Settings, and select Accessibility. Tap Touch, and then tap AssistiveTouch. At the next screen, turn on the switch for AssistiveTouch; a large circular mouse cursor should appear on the screen. Move your mouse around to see if the cursor responds to its movements (Figure A).
If a mouse using Bluetooth does not respond, swipe down to the section for Pointer Devices, and tap the entry for Devices. See if the mouse appears under Connected Devices. If not, tap the entry for Bluetooth Devices (Figure B). Let the Bluetooth search run to scan for and locate your mouse.
You can now move your mouse around, and the cursor will follow. Click your left mouse button to select an item. Right-click your mouse, and a menu pops up with different commands. From the menu, you can go to your Home screen, activate Siri, open Control Center, and view your Notifications. Click the icon for Custom to create your own custom commands (Figure C).
Click the icon for Device, and you can access more commands, such as volume control, screen rotation, and Lock Screen (Figure D). Left-click anywhere outside the menu to close it.
You can customize your mouse button actions. In Settings, go to Accessibility, Touch, and then AssistiveTouch. Swipe down the screen to the section for Pointer Devices, and tap Devices, then tap the entry for your mouse. Here, you can customize the settings for Button 1 (left button), Button 2 (center button or scroll wheel), and Button 3 (right button) (Figure E).
Tap on a specific button, and you can choose from a variety of commands (Figure F).