Yes please add this. This missing is keeping me from using firefox as my only browser. On Mac I got safari open additionally for sides I have to login to (so most of my use) and on Windows it is Chrome as those browsers support the Apple Keychain. It is free and the most easy to use for me and if Windows and Mac would have it in firefox I would uninstall Chrome in a minute and stop using safari at all.
If I understand it correctly, the upcoming release o#macOS Sequoia (autumn 2024) will have a dedicated password manager. So it is likely thatFirefox may access the passwords and, I hope, credit card information and so on.
Would be great to have this feature for people who are integrated into the Apple Ecosystem. With the release of Apple's latest Passwords app, it would be great to be able to autofill passwords directly in Firefox through an in-house extension or some other mechanism. This is currently the only feature missing that is holding me back from making a permanent move from Safari to Firefox.