Hello,
I’m new to Opensuse (a simple user from Linux Mint), so I tried to connect using my 3g key but with no luck. It keeps showing the unlock screen even though I entered the password and no further steps are made.
Any help please? Thanks 
What do you mean about “connect using my 3g key?”
If you’re really seeing a lock screen,
You should be entering your User Account Password, not some key for something else.
(Unless the two are configured the same)
TSU
Which desktop environment? Is it the keyring manager that’s requesting a password ahead of the connection process?