"Centralising Firebase / Google Analytics Screen Tracking In Android" @ http://blog.jakelee.co.uk/2018/10/22/centralising-firebase-google-analytics-screen-tracking-using-android-fragments

LoginFragment.kt

    override fun onCreateView(
        inflater: LayoutInflater, 
        container: ViewGroup?, 
        savedInstanceState: Bundle?
    ): View? {
        TrackingUtil(requireActivity()).track(TrackingUtil.Screens.Login)
        return inflater.inflate(R.layout.fragment_login, container, false)
    }

TrackingUtil.kt

import android.app.Activity
import com.google.firebase.analytics.FirebaseAnalytics
import com.ingenie.sensor.baseui.BuildConfig
import timber.log.Timber

class TrackingUtil(val context: Context) {
    enum class Screens {
        ChangePassword,
        Contact,
        Dashboard,
        DashboardInfo,
        ForgottenPassword,
        Info,
        Login,
        Registration
    }

    fun track(screen: Screens) {
        if (!BuildConfig.DEBUG) {
            FirebaseAnalytics.getInstance(context.applicationContext)
                .setCurrentScreen(context, screen.name, null)
            Timber.d("Sending screen view of ${screen.name}")
        }
    }
}

In LoginFragment.kt on Line 6

Instead of
TrackingUtil(activity!!).track(TrackingUtil.Screens.Login)

Try these:
TrackingUtil(requireActivity()).track(TrackingUtil.Screens.Login) which will force to get the activity automatically