Hey @Gaetcha. If the 1Password for Safari extension is installed in /Applications but does not appear in Safari > Preferences > Extensions, then let's try refreshing Safari's extension registrations manually with Terminal. To do this, follow these steps:
- Close all open web browsers.
- Open the Terminal app on your Mac: https://support.apple.com/guide/terminal/open-or-quit-terminal-apd5265185d-f365-44cb-8b09-71a064a42125/mac
- Paste the following into Terminal and then press enter to run the command:
~~~
/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -f -R /Applications/Safari.app
~~~
- Open Safari > Preferences > Extensions and try to enable 1Password for Safari again.
Let me know how that goes!