From https://forums.ankiweb.net/t/fedora-35-and-anki-2-1-47-updates-with-blank-anki-window/13431/13
Place anki.desktop into ~/.local/share/applications and then refresh desktop entries using xdg-desktop-menu forceupdate.
To install:
curl https://gist.githubusercontent.com/niklasdewally/2244835af079d1f251ebb69f31d97ed6/raw/00dd23f69bc486f31deb878995a7d1a12b2ccc3a/anki.desktop > ~/.local/share/applications/anki.desktop && xdg-desktop-menu forceupdate