Kotlin - How to animate transition between ActionBarDrawerToggle Indicator and supportActionBar Up Button

Question

I am quite new to Android Studio and Kotlin programming. I'm facing an issue regarding the animation of the left button of the Toolbar in my app.

I have an Activity in which I load different Fragments for different purposes. These Fragments can be opened using the Drawer Layout. Everytime I switch between two Fragments, the ActionBarDrawerToggle Indicator (the so-called "Hamburger icon") remains as it is, that is it remains the Hamburger icon. This is ok to me, I want this behaviour

Anyway, I have this Fragment (say A) where there is a circular ImageView with a click listener that, when clicked, opens - with a smooth and completely working animation - a new Fragment (say B) in which the Image is shown in full size. Here comes my problem. I want that in Fragment B the Hamburger icon slowly transform into the supportActionBar Up Button (or back button), which will allow me to click it and go back to A.
In this moment I have successfully set the change of the two icons when the Fragments change, and I can see Hambrurger in A and the back arrow in B, but I can't find a solution to have the animation

Thanks to all in advance!

Below is my code:

MainActivity

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        //set toolbar
        setContentView(R.layout.drawer_home)
        toolbar = findViewById(R.id.drawer_toolbar)
        setSupportActionBar(toolbar)
        //set drawer layout
        drawerLayout = findViewById(R.id.drawer)
        navigationView = findViewById(R.id.navigationView)
        navigationView.setNavigationItemSelectedListener(this)
        actionBarDrawerToggle = ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.close, R.string.open)
        drawerLayout.addDrawerListener(actionBarDrawerToggle)
        actionBarDrawerToggle.isDrawerIndicatorEnabled
        actionBarDrawerToggle.syncState()
}

//I call this function inside the Fragments A and B where I want to set the Hamburger Icon and the Back Button when needed
fun showBackButton (enable: Boolean){

        if(enable){  //show back button
            //block drawer 
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
            //remove hamburger icon
            actionBarDrawerToggle.isDrawerIndicatorEnabled = false
            //show back button
            supportActionBar?.setDisplayHomeAsUpEnabled(true)
            //set listener on up button
            if(!toolBarNavigationListenerIsRegistered){
                actionBarDrawerToggle.setToolbarNavigationClickListener {
                    //il back button è stato premuto, ritornare indietro nella backstack
                    val fragmentManager = supportFragmentManager
                    fragmentManager.popBackStack()
                }
                toolBarNavigationListenerIsRegistered = true
            }
        }else{  //show hamburger icon
            
            //unlock drawer
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
            //disable back button
            supportActionBar?.setDisplayHomeAsUpEnabled(false)
            //enable hamburger icon
            actionBarDrawerToggle.isDrawerIndicatorEnabled = true
            //cancel listener on up button
            actionBarDrawerToggle.toolbarNavigationClickListener = null

            toolBarNavigationListenerIsRegistered = false
        }
    }