Currently, there is no such command to force FCI to Domain PC however you can try to Verify that the files are classified and then try creating the classification rules.
The below article sheds some insights about the whole process and you might get some valuable ideas to achieve your goal.
File Classification Infrastructure (FCI) - Classification and policy
You can also recheck your steps with the below article.
Deploy Automatic File Classification (Demonstration Steps)
Hope this resolves your Query!!
--If the reply is helpful, please Upvote and Accept it as an answer–