Hello spatialdigger,
You need to have Professional edition license activated on the computer, where stand-alone Metashape Python module should be used.
If the license has been already activated via Metashape Professional GUI on that machine, you can create agisoft_LICENSE environment variable as a path to the .lic file containing folder and reboot the system. Python module than will properly used activated license on the computer.
Standard edition license doesn't interfere with Python module (as it is not even checked by Python).