I still have this same problem 3 years later in MacOS 14.2.1. I installed the app from the Mac store. At first the extension showed up in the browser toolbar. Then it disappeared from the toolbar and I had to re-enable it from the safari settings. Then it disappeared from the safari settings as well. I am not interested in running commands manually to reregister the extension. My LastPass extension that I use for work has never had this problem.