You can enable Universal Control if you are running macOS Monterey beta 5 on your Mac, but it is a slightly tricky procedure to follow.
Apple hasn't Enabled Universal Control Just Yet, However, You Can Enable it in macOS Monterey Beta 5 and Up Using Terminal Commands
Apple's announcement of macOS Monterey confirmed one thing; the iPad and Mac are two devices that will work even more closely together when updated to the latest software later this year. The key thing that makes this more exciting is Universal Control, allowing you to move the mouse pointer from one device to the other, copy and pasting images, videos and whatnot. But, so far, Universal Control is a no show, signaling towards the fact that this feature won't make it to everyone on launch day and is indeed planned for a later update to macOS Monterey and iPadOS.
Interestingly, the necessary files needed to make Universal Control work are actually present in macOS Monterey and they are simply disabled on the user-end. Thankfully, you can actually enable it all and take Universal Control for a spin between two Macs. But, there is a huge risk you will be taking here as it involves playing around with the file system, Terminal commands and whatnot. If you are completely fine with that, along with the fact that this method is supremely complex, then head over to Github right now and take a shot at enabling Universal Control.
Remember, there are a lot of things that can go wrong here, even a bricked Mac if things don't pan out really well. So please, proceed at your own risk, and we will not be held responsible for anything that could go wrong here.
Installing macOS Monterey for the first time? Be sure to check out the following: