I think phosh.service acts as the display manager and does the autologin, so I think you'd need to disable phosh.service and install an alternative display manager like lightdm to let you pick the user to use.
Been trying using lightdm but cant get to the login screen to change user. After enabling lightdm and reboot only get black screen.
I have created the user and installed lightdm, without problems. But it is not functional because you need a keyboard to be able to write the username and password.
does anyone know how to invoke the mobian on-screen keyboard for lightdm? with that it would work.
Sorry but I don't speak English, I use a translator.
I got it using gdm3
First you register a new user from the console with the command: (change diego for your name)
sudo adduser diego
Install gdm3 this is the process
first update the repositories using:
sudo apt update
then we install gdm3
sudo apt install gdm3
It is not necessary to restart, and do not despair that it takes a little while for the gdm3 screen to appear, but it appears as you can see in the images above.
when you get the gdm3 screen you will see the two users:
the touch screen works normally. You select the new user (if not, it's not funny)
important in bottom gear select phosh environment
and to make the keyboard appear you drag from bottom to top.
and enjoy the new user.
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I have found a small bug in the use of gdm3. When you start the phone, you barely have time to see the gdm3 screen.
The solution I have found right now is the following:
You enter with the default user, the first on your list. In my case it is mobian as you can see in the first photo that I have passed.
When you are with that user you go to a command console and use the following command:
sudo systemctl restart gdm3
and it is fixed until the next reboot of the phone.
You can exit and change users as many times as you want, gdm3 will only fail when starting the phone. but we already have a solution.
Enjoy whoever wants to use it.