I have submitted a crash report. I mentioned in it that I had not posted here about the crash but decided to do so in case anyone else has experienced it. I created a new login item, saved it and then needed to edit the user name. As soon as I clicked on the Edit button 1Password crashed.
(The crash report was not submitted from my registered email address but does refer in the notes to my registered email address.)
1Password Version: 7.1.BETA-1
Extension Version: 184.108.40.206
OS Version: macOS 10.13.6
Sync Type: WLAN