Desktop app is great and perfect. The Firefox extension is abysmal. I've experienced almost all of the other 1 star ratings. The extension consistently (8 out of 10) fails to unlock when Firefox is started (even with the desktop app already running). Repeated clicks on the extension icon eventually yield "something went wrong, click restart the app". Sometimes the restart works and sometimes it doesn't. Most of the time I have to keep switching back to the desktop app to copy and paste user names and passwords. BTW Nordpass has not implemented a right click menu for copy/paste in the notes section and elsewhere; have to resort to CTRL-C and CTRL-V.
I have had a paid premium account for about a year. During that time there have been extensive communications with Nordpass's support group. It is pretty much always the same: "Uninstall, reinstall, send us the logs and we will let you know if we figure it out."

The problems persist. Shame, but it apparently isn't ready for prime time. If all you want is a desktop app, then this is a great product. If you want a Firefox extension, read all of the negative reviews and save your money and time.