@DimiPana Hi in the latest version of Opera
Opera One(version: 124.0.5705.15)
Chromium version:140.0.7339.249
on Win10.
To export passwords :
Enter the following in the address bar at the top of the browser window :
opera://password-manager/passwords
Then on the left side of the window there is now a new settings option (unlike you would expect ! this does NOT take you back to the previous page) click on this and then the settings for the passwords are there.
One of these half way down is the option to export passwords.
I hope this helps. I came across this post while trying to work out how to do it myself and saw there was still no answer. I know in some versions of one browser the ability to export passwords was turned off and you had to go into the options of the browser and enable the option before you could get the three dots. Can't remember if this was Opera or Chrome. They all seem to blend together in my head after a while 
Anyway found the above steps in another post on the web and found it worked for me. So came back here to spread the resolution to the issue (for now at least !).