can't change sddm display manager theme

Question

I am using Debian 10 with Xfce desktop environment. I recently changed to sddm display manager. However no matter what I do, I can't change the display manager theme (only the debian-maui theme appears). I want to change the theme to a custom one which I have downloaded from git hub (I tested it using sddm-greeter --test-mode --theme [theme location] command and it works fine). Can anyone explain me clearly how to do it? (There were no sddm config files to be found and even when I manually created them, they seem to have no effect on the theme of the display manager despite whatever necessary changes made to the config file)

[Please keep in mind I use Xfce desktop environment]

Answer 1

In Ubuntu 20.04.3 LTS new sddm themes you can find by:

apt search sddm-theme

and instll it by e.g.:

sudo apt install sddm-theme-lubuntu

After instalation new theme will be placed in /usr/share/sddm/themes/ In the same dir there is a link:

ubuntu-theme -> /etc/alternatives/sddm-ubuntu-theme/

pointing to /etc/alternatives/sddm-ubuntu-theme

In /etc/alternatives there is a link you can change to point to theme you like, e.g.:

 /etc/alternatives/sddm-ubuntu-theme -> /usr/share/sddm/themes/maldives/

and this link specifies default config

To check where and which is the system default config file placed in you can run:

sddm --example-config 

and analyze [Theme] section.