Working in my home office, I've currently connected my iPad as a third screen to my MacBook Pro. My Thunderbolt display being the second screen.
You'll need to install Duet both on your Mac and on your iPad: https://www.duetdisplay.com
It uses a USB cable to connect and also works on older Macs and iPads (in contrast to Apple's own solution to connect the iPad to your Mac).
alwayslockyourbike
Working in my home office, I've currently connected my iPad as a third screen to my MacBook Pro. My Thunderbolt display being the second screen.
You'll need to install Duet both on your Mac and on your iPad: https://www.duetdisplay.com
It uses a USB cable to connect and also works on older Macs and iPads (in contrast to Apple's own solution to connect the iPad to your Mac).