can't import android.support.v4.app notificationcompat in android studio?-CodePudding

I was learning android notification tutorial using

While this is not enough, because latest build tools will not support deprecated libraries, you have to keep compleSdkVersion 28 or below. You are also required to downgrade your Android Gradle Plugin to 3.6.4 and gradle wrapper to 6.0

Make sure these lines are not present in gradle.properties

android.useAndroidX=true
android.enableJetifier=true

Now you can follow the above tutorial.

Use

android.arch.core:core
android.arch.core:common

instead of 

androidx.arch.core:core-common
androidx.arch.core:core

Here is the full list of equivalent artifacts of support library to androidx

I do not recommend you to follow above tutorial find latest tutorial. Tech is rapidly changing, following an outdated tutorial might slow your learning process and keep you behind.