I'll say straightaway that I don't actually have Photo & Graphic Designer but I can find no reference anywhere to the software including any facial recognition facility. Magix Photo Manager Deluxe does include this, so are you actually asking about that software?
Thank you for the information about the exact app you are using.
Have you read the built-in Help file on "Face ID"? Have you tried to follow the routine it describes? What happens, or doesn't happen, if you do? IOW, can you tell us exactly what you have done so far that does not produce the results you are expecting?