Unsupported Python project

I tried to use codebeat for my Python project at

but I got the message "unsupported@.

Then I renamed the source file to end in .py but it was still unsupported.

I moved the .py file to a subdirectory src/ but it is still unsupported.

I even renamed the GPL LICENSE.txt to LICENSE but it is still unsupported.

Why it is unsupported?