how to start and stop the google sdk service

Question

Hi on my old raspberry pi 3b with raspbian stretch i installed the old google assistant sdk: https://developers.google.com/assistant/sdk/guides/library/python/ and started this with the google-assistant-demo.

I cleaned by rpi and installed the service - the latest image buster from raspberry pi org - and i followed the google assistant procedure https://developers.google.com/assistant/sdk/guides/service/python/

what i missed is the google-assistant-demo script. in my previous configuration ihad a bash script /home/pi/google-assistant.sh with

#!/bin/bash
source /home/pi/env/bin/activate
/home/pi/env/bin/google-assistant-demo

and a file /etc/systemd/system/google-assistant.service with:

[Unit]
Description=Google Assistant

[Service]
ExecStart=/bin/bash -c '/home/pi/google-assistant.sh'
Restart=always
User=pi

[Install]
WantedBy=multi-user.target

i installed the service with sudo systemctl enable google-assistant.service.

i could start and stop this google service How can i start the latest sdk as a service and put it on or off ?