The Flutterfire team removed Firebase Deeplink from firebase_core, and they made a new major version 4.0.0, so now segment_analytics_plugin_firebase is not compatible with firebase_core ^4.0.0
Because segment_analytics_plugin_firebase 1.0.1 depends on firebase_core ^3.6.0 and no versions of segment_analytics_plugin_firebase match >1.0.1 <2.0.0,
segment_analytics_plugin_firebase ^1.0.1 requires firebase_core ^3.6.0.
Could you update the firebase_core version in segment_analytics_plugin_firebase?