A simple yet effective way to add a refreshing background on the jellyfin login page it now auto reloads the background image after 10 seconds
cd /usr/share/jellyfin/web
sudo wget https://github.com/BobHasNoSoul/jellyfin-fanartbackground/archive/refs/heads/main.zip -o fanart.zip
sudo unzip fanart.zip
Once unzipped add the following to the end of your index.html file using sudo nano index.html
(and insert the following just before the final tag
<script src="jellyfin-fanartbackground-main/cssbuster.js"></script>
Then simply refresh the page if you still have issues clear your cache
You can change all images by replacing the .jpg in fanart folder
If you want more or less images in rotation modify the cssbuster.js with a text editor (this will be pretty self explanatory when you see the file)
Not all images work well on mobile phones (some vertical displays)
each reload of the web page will grant a random background from your folder of fanart (can be replaced with any images you want, increased or decreased). after a reload after a reload there are more but i would be here forever if that was my goal to screen cap all of them.