Problems installing the kwb integration

Hi, i use home assistant on a raspberry pi 3 and i am not an experienced user.
I have a problem with the installation of the kwb integration (KWB Easyfire - Home Assistant).
The data are provided by a usb-to-serial adapter which is plugged in the praspberry py. I have tested the part already with a different pc an it works fine.
I added the platfom, name, device, type and raw part to my configuration.yaml the sensor showed up as “not available” . As device i use ttyACM0 because thats how the stick shows up under system → hardware.

About the last step i am not absolutely not shure. I guess i have to install pykwb (GitHub - bimbar/pykwb) but i don’t know how to do it. What i tried is:
I copied all the pykwb files in homeassistant/custom_componenst/pykwb and run the command “python3 setup.py build” as shown in the pykwb readme. But i get the warning “byte-compiling is disabled, skipping”. With sudo i don’t get a warning.
Sudo python3 setup.py install did something but showed a text i should not rund setup.py directly and use pypa/build and pypa/installer.
When i try pip3 install pykwb i get an error “externally-managed-envirment” and i should use apk or use a virtual environment.
I try to find out how to do all that but as i said i am just a beginner.
So until now i just can see the sensors but they are all “not available”.
If somebody could give me a hint how to install pykwb or if i have to do anything else i would be very thankful.