How did you install snapd? Which instructions were you following?
The ones in OpenSuse wiki or the ones linked in the Snap Store website.
They are practically the same except for:
Swap out
openSUSE_Tumbleweed
for your chosen openSUSE distribution, such asopenSUSE_Leap_15.5
.
Did you swap the version when adding the repository?
I’ve found that it was a problem for one user before:
Also do the snapd related services are running.
systemctl status snapd.service
systemctl status snapd.apparmor.service