Flex Pitch: I can not figure out how to get the track to allow Flex Pitch.

I just started using the Flex Pitch option (Logic ProX) for the first time and ran into the scenario where the track I am trying to use this with will not analyze. I've research all of the place and can not seem to find the solution. The only solution I keep hearing about is to Flatten or Flatten and Merge. However, I can't seem to get to work either. I am using a MacBook Pro 13" with Mac OS Ventura and Logic ProX 10.7.7. Anyone out there know a solution to this?