While the Mac version of FreeCAD will open Python scripts from BikeCAD with no issues. Currently, the PC version of FreeCAD version 0.21.2 requires that an extra Python library be installed first. In an earlier video, I explained how you can run a Python script called macro.py to install the Requests library. While this should work for most users, a few have reported issues presumably due to conflicts with other Python libraries on a given machine. For those still having issues installing the Requests library, here is an alternative solution. Download the file requests.zip from bikecad.ca/requests.zip . Unzip the file and place the five folders inside the directory C:\Program Files\FreeCAD 0.21\Ext as you can see here.
After restarting FreeCAD you should be able to open any Python script exported from BikeCAD Pro.