How to install python application with tkcalendar module by pyinstaller?

I'm trying to install python application on Windows with pyinstaller where I'm using tkcalendar. Application is working but the tkcalendar.Calendar isn't.

When I'm running application without installation everything works but if I do this, Calendar widget does not appear. I think that pyinstaller sees this module but he has problems with modules that tkcalendar is using. I tried to run pyinstaller with --path=/.../python/Lib/site-packages but this didnt worked. Also copying module files to application directory didn't help.

The issue does not come from tkcalendar but from the fact that PyInstaller does not detect second level imports. A way to solve this issue is explained in tkcalendar's documentation in the HowTos section:

When bundling an application with PyInstaller, there is an issue with the detection of the babel dependency of tkcalendar. This can be fixed by using the --hidden-import option:

$ pyinstaller --hidden-import babel.numbers myscript.py

or by editing the .spec file:

hiddenimports=["babel.numbers"]