How to change setDisplayShowHomeEnabled(true) in different fragments?

Question

Android

There is an activity that holds a fragment, if I create a backarrow in an activity, then it is created in all the fragments that change in it. I need this button to not be in the very first fragment, and when I move to other fragments, it appears. Tried tracking through fragmentManager.backStackEntryCount but the button just doesn't show up. It appears only when I create it in mainactivity in mainactivity.
Or can it only be done in a bush bar?

Answer 1

I clambered a lot of sources, but nevertheless I found a solution from an Indian in a video on YouTube.

//MainActivity
 private lateinit var navController:NavController
 override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        navController=Navigation.findNavController(this,R.id.fragment)
        NavigationUI.setupActionBarWithNavController(this,navController)
    }

    override fun onSupportNavigateUp(): Boolean {
        return navController.navigateUp()
    }