TYPO3 Extension BeLogin Images
Display random Background Images from different sources at your TYPO3 BackendLogin Page.
Simply install the extension with Extension Manager or Composer
composer require svenjuergens/belogin_images
then take a Image Provider.
If you want to use Unsplash you can build an URL on https://source.unsplash.com/)
On tab "Folder" set a path to a folder with Images, from which a random one is displayed.
IPmask in ExtensionManager settings to restrict the output to a specific IP.