Alternatively, you can ask Gramps directly about the current path to the add-ons.
Use the Python Evaluation gramplet and paste the following 5 “Evaluation” lines, then press the Apply button:
from gramps.gen.const import USER_DATA, USER_PLUGINS
print ("User Directory:")
print (" " + USER_DATA)
print ("Add-on plug-ins folder:")
print (" " + USER_PLUGINS)
