In case you cannot see the folders like in the tutorial video, do it like this (link). Problem is that without Apple Motion not installed, these folders are not generated. So you need to do it manually:

It seems that nobody at Apple OS-Development talks to anyone at Apple’s FinalCut Department.

1. Open System Settings
2. Open Security
3. Go to the Privacy Tab
4. Scroll to “Screen Recording”, unlock the lock and click the + icon and then add FCPX to the list of allowed apps.
5. Potentially whitelist FCPX to any other privacy setting in that list, such as Disk Access and Accessibility.

OPTIONAL: Disable background rendering via FCPX’s settings.

It doesn’t kill the Spinning Ball completely but sure enough FCPX becomes a LOT more responsive. It seems that the more Privacy Rights you grant access to, the faster FCPX becomes in general.