How to change the Gnome login interface picture?

1、Debian12 system, Gnome desktop, how to change the login interface picture? Thanks!
2. How to enable login sound in debian12 system and Gnome desktop? Thanks!

  1. You can change your user picture in the user settings of gnome-control-center.

  2. To have a sound play after login you need to use a sound theme that comes with one. There are not many sound themes and the default sound theme does not have the corresponding sound (desktop-login). However it seems like Debian has a package for deepin-sound-theme which comes with a desktop-login sound. If you install that package and then run gsettings set org.gnome.desktop.sound theme-name deepin to select that as sound theme, that should work.

Thank you for your reply. How should I set the picture of the gnome login interface?

Thank you for your reply. I have set the user avatar. How should I set the background image of the gnome login interface?

It is not possible to set a background image for the login screen.