2019 iMac as a 2nd monitor for my MacBook Pro
I am trying to use my 2019 iMac with Big Sur 11.6 as a 2nd monitor for my MacBook Pro with Monterey 12.1 with a USB-C cable but it's not showing up under settings>Display Preferences and Command-F2 doesn't do anything. When I connect the two devices my MacBook Pro just starts charging. Would love to know what I am doing wrong or if this is a bug.
iMac 27″, macOS 11.6