On https://raspi.debian.net/ one time the image was broken, so I had to built it myself.

https://salsa.debian.org/raspi-team/image-specs

The makefile can create you a yaml file for your pi model and your release of Debian. Then you can edit that file to do whatever you want to the system, before making it into an image.

For example:

- In the section apt/packages, add sudo.

- Create a user, add it to the sudo group, with password "" and /bin/bash for shell

- Create a .ssh for your user, and echo in your SSH public keyboard

That way you can boot into your new Debian system without having to have a screen.

As soon as you login, the first thing you should do is reset your own password.

By doing -p "" we set the password to empty.

If we had not done -p "" the password would have been empty but locked, so you wouldn't be able to sudo.

Also go ahead and lock your root user password, which you could also do from the file.

Build your image, and go.