Not seeing apps in Available Applications

[BrunoGenoveseGist]

My goal was to backup my contacts. I am using the CalyxOS deGoogled Android 13 distribution, on an ancient Pixel 3.

• As required I installed OpenKeyChain, created a key, and setup the Backup encryption settings.
• The Only application that shows up in Available Applications is Notes. Nothing else.
• There another / default Backup application that came pre-installed with CalyxOS but I could not make it function for the backup. It has options to backup on a USB flash drive (did not seem to work, maybe I have to configure access to it?), a webdav server (no luck finding a trustworthy one) or Nextcloud (I am not ready yet to buy a box for it). I am not using it but I have not yet uninstalled it. That is how I went looking and decided to try your backup app.

Do I need to grant some access rights? Did I miss some setup?