I am using androidx.core.app.NotificationChannel and androidx.core.app.NotificationChannelCompat to resovle the android compatible problem according to (Androidx API reference)[https://developer.android.google.cn/reference/androidx/core/app/NotificationChannelCompat].
But even I add implementation "androidx.core:core:1.3.1 in my build.gradle file, Android Studio prompts me can not resovle symbole NotificationChannelCompat.
Why? I do not want use SDK version conditional statements to fill my source code.