Simplest way to start after Manual Hass install on RasPi

I followed the installation instructions at https://home-assistant.io/docs/installation/raspberry-pi/

Now, what is the simplest way to start it, maybe after a reboot?

It should autostart as a service

The instructions to set up autostart are here

Maybe the instructions have changed. When you install via https://home-assistant.io/docs/installation/raspberry-pi/, you need to activate Python and then run hass. It does not set up autostart. The link you provided (Autostart using systemd) assumes hass has been installed. When I enter “whereis hass” it does not list anything (only “hass:”). Some step is missing to enable/install hass. Can you help? Thanks