I know that I said that I wouldn’t write about this, but enough of this is on the internet right now that I feel comfortable in doing so now.
Caution: This process may affect your Mac, or even the status of an account that you might log in with in an app. Updates will not be available for these apps and will need to be maintained manually. Only apps that you own will work on your computer, since they are digitally signed to your Apple account.
Some apps don’t even work at all, so do not get your hopes up. Some apps may also crash your Mac. Proceed at your own risk.
Download and Install Apple Configurator 2. It’s available on the Mac App Store. Make sure that you’re logged into your account.
Connect an iPadOS or iOS device to your Mac. You may need to unlock it to get it to show up inside of the app.
Click the ‘+ Add’ button on the top row of the window in Apple Configurator 2. You should be able to scroll through all of the apps that are contained in your Apple account. Find one that you want to install on your Mac, and install it on your device if it is not already on there. Go through the menu and make sure to install it again, so that you hit an error message telling you that you already have it installed on your device. Don’t click cancel.
In the Finder, hold option and enter the “Go” menu. “Library” should be visible. Go into: Group Containers -> K36BKF7T3D.group.com.apple.configurator -> Library -> Caches > Assets -> Temporary Items -> Mobile Apps. Copy the .ipa file to your desktop. As soon as it has been copied over, you can cancel out of the Apple Configurator Screen. The “Temporary Items” directory will delete itself.
Open Terminal and paste in:
sudo xattr -cr
Drag the .ipa file into the Terminal to populate the path. Hit enter (you may need to enter your system password). Now, you should be able to double click the .ipa file and have the forbidden app installed on your Mac.