How to replace a fragment using NavController.navigate instead of adding it on top

Issue seems to have occured because of these two lines:

val host = NavHostFragment.create(R.navigation.navigation_register_login)
supportFragmentManager.beginTransaction().replace(R.id.nav_host_fragment,host).setPrimaryNavigationFragment(host).commit()

I guess they shouldn't be called, and all basic requirements are fulfilled by this line in layout:

android:name="androidx.navigation.fragment.NavHostFragment"