I installed the 1password for Linux Beta in the Crostini Linux apps beta on my Chromebook and when using the browser login option (to avoid typing a ton) after selecting my account I got the error "Google Chrome OS can't open this page." I wasn't too concerned since this is quite common because ChromeOS doesn't "see" the protocol handlers from Linux and would require an extension or Chrome App register to handle onepassword:// links.
The simple workaround is to open the Terminal app (where you probably ran the
apt installation commands) and run
xdg-open "onepassword://......." and the double quotes are necessary around the onepassword://stuff that you can copy to the clipboard if you click "still not working".
I don't know if there is a good way yet to register a Linux app to handle links from the ChromeOS browser and launch into the app, but I've been exploring a bit more because it seems that maybe garcon could handle relaying links into the Linux VM container for certain things.
1Password Version: 0.9.6
Extension Version: 1.22.3
OS Version: ChromeOS 86.0.4240.199
Sync Type: Cloud