re: shortcut to enable iPad as second display

An iPad can be used with a compatible Mac to extend the Mac display to the iPad using the Catalina/iPadOS Sidecar feature.

Use iPad as a second display for your Mac – Apple Support

An alternative third-party product, Duet, can be used to extend a PC or Mac display to an iPad:

https://www.duetdisplay.com/

You should note that older models of iPad do not support iPadOS16 Stage Manager feature.

Hi Randy209,

Thank you for participating in the Apple Support Communities. It looks like you came from the following support article: Use an iPad as a second display for a Mac - Apple Support

If you would like to leave feedback for Apple on this, here is where you can do so: Product Feedback - Apple

Have a great day.