@maxin2003 I was able to test paramountplus signed in with an account.
In Opera, goto the URL opera://browserjs and disable browser.js for the session so that the paramountplus.com page doesn't go black and so that the sign in page doesn't say "forbidden".
Once signed in, go to the page for a movie/episode you want to play.
Then, goto the URL opera://extensions, turn on developer mode, click "load unpacked" and point it to the extracted folder of my paramountplus.com workaround extension where manifest.json is at. That will load the extension. Then, at the URL opera://extensions, turn on "Allow access to search page results" for the extension.
Then, on the movie/episode page, reload the page and play the video. If it says "optimzing your video playback" and then goes back to not playing the video (but doesn't give you an error), click the video to play it again and it should work. Only had to do that once.
Tested with the Joe Dirt movie and a South Park episode. The both played fine in Opera after a few ads played.
I did not test with any adblockers on, so you might want to disable Opera's adblocking and tracking protection at the URL opera://settings/privacyProtection and any adblocker extensions first. You also might want to disable lucid mode at the URL opera://settings/lucidMode first (I didn't need to though).