The documentation to install this is somewhat lacking. Assuming you are running Home Assistant as user “homeassistant”, you’ll need to do this:

Connect the camera and enable it as detailed here – https://www.raspberrypi.org/learning/getting-started-with-picamera/worksheet/ don’t reboot it yet.

update the firmware: sudo rpi-update

reboot

give the homeassistant user permissions to read the device by adding them to the “video” group – sudo usermod -a -G video homeassistant

You’ll need to restart home assistant to pick up the group changes