u/W4T_92

Since version 8.12.10 (iOS and iPad OS), 1Password is using the native AutoFill functionality on iOS. That means that the inline extension doesn't show anymore on Safari and that it is not possible to generate a Fastmail alias with 1Password anymore.

I won't say that I switched to 1Password for this reason, but the Fastmail integration was part of the reason. I hope the devs will find a way to implement it again.

The support team told me to manually generate an alias on the Fastmail app and to copy/paste it on 1Password when creating an account, but I think part of the added value was to do it directly from 1Password.