execv(python): No such file or directory / python working directory

I just freshly installed linuxcnc 2.9 pre on debina bullseye
The system works but now I want to include some python code.
at the line:
loadusr -Wn compensation python compensation.py filename.txt
it gives the error 
execv(python): No such file or directory

The file is the configs/"configurationName" folder.
Where is python looking for the file?

Thanks
A.

Thanks I just set
chmod 777 compensation.py and filename.txt

no change.
the working directory of linuxcnc ist the directory of the config ?
so /home/user/linuxcnc/configs/maschine ?

even with loadusr -Wn compensation python /home/work/linuxcnc/configs/SilverGlider/compensation.py

it gives this error

try:

loadusr -Wn compensation python3 compensation.py filename.txt

Wait, did you add the compensation component to linuxcnc?
If so where did you add it?

Also qtdragon_hd in 2.9 supports built in gcode ripper and z level compensation.
Are you instead trying 3rd party code?
Could you give more information.

I just did a Debian upgrade and adding the "3" to python fixed it for me.

Thanks
srl