UPDATE: Now, the issue is fixed upstream.
If you're on openSUSE Tumbleweed with the latest update, you will notice that you can't not use any
sudo command due to SUSE Bug 1205094. However, since this is openSUSE, you can easily fix this issue with just a few steps through GUI. No command is needed!
Install YaST's Sudo add-on from GNOME Software.
Open YaST Sudo, then add your user name to the Sudo Configuration.
The configuration should look like this:
It's done! Now, you can use
sudo like before. I hope this helps 💪