Posting this message here so that it will show up in the archives when people search for it.
After downloading the 64-bit appimage, I got this error:
> ~/digikam-5.8.0-01-x86-64.appimage
digikam: error while loading shared libraries: libopenal.so.1: cannot open shared object file: No such file or directory
It is solved by installing the missing library:
sudo apt install libopenal1
Tac