As witten by @anon11595408 a standard Gnome installation does not have icons on the desktop any more. You have the dash where you can stick the programs you need often.
But there is a Gnome shell extension which adds this:
https://extensions.gnome.org/extension/2087/desktop-icons-ng-ding/
You can install the extension via the AUR and yay too:
yay -S gnome-shell-extension-desktop-icons-ng
But there are many reasons why the Gnome developers removed the icons from the desktop.