Native, KMM or Flutter for Android dev amateur?

I am an amateur developer. I can build simple Android apps with Kotlin. No experience in iOS development at all.

I want to create an app for me and my friends. The problem is, most of my friends uses iPhone, including myself. The app will use Firebase cloud notifications, Firestore and Firebase authentication.

Following are my guess. Native iOS: Steep learning curve, but probably the easiest out of the 3 options overall KMM: Probably the least to learn, but may encounter issues with Firebase SDK etc Flutter: Steep learning curve, also may encounter issues with Firebase SDK etc

Any advise?