Hello @bookwar ;
There are scripts as per gdm doc’s
Interfaces which continue to be supported in a stable fashion include the Init, PreSession, PostSession, PostLogin, and Xsession scripts.
Some daemon configuration options in the <etc>/gdm/custom.conf file continue to be supported.
Also, the ~/.dmrc, and face browser image locations are still supported.
There is discussion of the PreSession, PostLogin, and PostSession scripts being used for user customization options. I found the info at https://help.gnome.org/admin/gdm/3.26/overview.html.en
[Edit] I’m thinking PreSession sets EN Language/Keyboard, PostLogin sets it to RU. WDYT? Just not sure if you can do it via gdmsetup or need manual intervention, probably the latter.
Have you checked in the settings ? Region & Language, there you have the Login Screen option. As I understood if you use GDM as Display manager, it also should be used for locking the screen. Just in case you prefer the Gui version to solve your problem.
As you can se the Display Manager is shown there. On my example you see that GDM is the default (1). I do also have LightDM (2) but it is stooped. If you have something else than GDM on (1), this could be the reason for the absence of the config in the settings.
And also, just with Gnome 45 you see this settings. There is a tool you can install in Software GDM Settings, this is what I have installed maybe this is what you just need?
I haven’t tweaked anything on the system on that level, it is a default Gnome Workstation setup, but it was upgraded from a single install for a couple of years, so there might be impact of the upgrade process from earlier GDM/Gnome versions somewhere.
Here, on fresh install of F39, Settings:Region and Language has separate panels for “Your Account” and “Login Screen”. I think the “Login Screen” only appears when you have more than one user. I always create two users.
I’ll try and create a user to test that out though.
[edit] So you are correct. The option for login keyboard selection appeared after I created another user.
[edit 2]: If you remove the second user the option to select a different login keyboard disappears. Shouldn’t this be there for single users as well?
It really looks like … the Gnome Manual shows to add this option separately. I just forgot that Gnome is still hiding config options and that this has to be added with dconf (Using long time the Mate-Desktop).
So the extension free solution/wokraround for the problem would be to create a second user like “dummy” and just deactivate with:
sudo usermod -L -e 1 dummy
I tested it and the option in the settings not disappears anymore.
p.s.
I changed the title to see that it is not depending on GDM as @vgaetera proposed.