I'm using Firebase passwordless login on my Android app with no problem but I can't find a way to test it on iOS because the email link always redirect to the App Store, which is the escape route in case it doesn't find the app installed.
On Android, the system recognizes the debug/test version as the app to open and everything works fine. But on iOS it seems the Testflight version isn't recognized as the same app, thus escaping to the App Store. And yes, I'm using the same app identifier otherwise the compilation wouldn't appear on the Testflight.
Same problem while debugging connected to the computer without using the Testflight approach.
I know Firebase has the Apple login (beta) option now, but I'm using flutter and things aren't working well for now so passwordless login is the best way to go.
I found out that I was missing a couple special steps needed just for iOS.
This page helped me adding the missing steps.
Now I can test the app on the simulator. I haven't tested it on Testflight yet.