import name.cpython-38-darwin.so in editor fails

Allthough the file "name.cpython-38-darwin.so" is inside the project folder, the import command: "import name" in the editor fails with "No module named   name.cpython-38-darwin" remark. Using the Python Console there is no problem to import and run this file with the same command. The file "name.cpython-38-darwin.so" is fortran interface created with F2PY on Mac. I run this project in a virtual environment with the interpreter python 3.8. In the settings for the interpreter I am not able to check the option "Inherit global site-packages", because the "OK" button will not turn blue. Maybe there is a connection. I would appreciate if anybody could help me to import this type of file in the editor. Thanks