AndroidX MultiDex not found

android.enableJetifier=true does not make the least sense, while being able to replace it.

you can simply add it as a dependency, without non-transparent mangling of name-spaces:

implementation "androidx.multidex:multidex:2.0.1"

If you are using androidx you should add MultiDexApplication(reference from androidx) to your manifest file.

<application
        android:name="androidx.multidex.MultiDexApplication"
        .....></application>