How to implement a counter in actionBar but in kotlin

Question

I ask this question because I have searched everywhere and I can't find anything to solve the problem. As the title says, I can't find anything in Kotlin, everything is in Java and I'm new to Kotlin. I need to do something, as in the image below. I have seen the following links but they do not particularly work for me:

Actionbar notification count icon (badge) like Google has

How to get text on an ActionBar Icon?

This is the code that I have and what is not working for me is the item just from the counter, which I should call a TabListActivity (which shows me a list), but it does not.

OnOptionsItemSelected does not recognize me when I click on the item, I know because I use Debug.

This is in my main activity called TabActivity.kt

 override fun onCreateOptionsMenu(menu: Menu?): Boolean {
             menuInflater.inflate(R.menu.tab_menu, menu)

         countButton = menu?.findItem(R.id.tab_list_button)
         countButton?.setActionView(R.layout.tab_button)
         var notif = countButton?.actionView as RelativeLayout
         var tv: TextView = notif.findViewById(R.id.tabCount)
         tv.text = TabInfo.count().toString()
         countButton?.title = tv.text

         return super.onCreateOptionsMenu(menu) }

override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            R.id.forward_button -> {
                TabInfo.currentWebView().goForward()
                refreshForwardButton()
            }
            R.id.reload_button -> {
                reloadCurrentTab()
                return true
            }
            R.id.tab_list_button -> {
                val intent = Intent(this, TabListActivity::class.java)
                startActivity(intent)
                return true
            }
        }

        return super.onOptionsItemSelected(item)
    }

My menu is called tab_menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item android:id="@+id/forward_button"
          app:showAsAction="collapseActionView"
          android:title="@string/go_forward"
          android:icon="@drawable/ic_arrow_forward_black_24dp" />

    <item android:id="@+id/reload_button"
          app:showAsAction="collapseActionView"
          android:title="@string/reload_page"
          android:icon="@drawable/ic_refresh_black_24dp" />

    <item android:id="@+id/tab_list_button"
          app:showAsAction="always"
          android:title="@string/number_tabs"
          android:actionLayout="@layout/tab_button"
        />
</menu>

My layout is tab_button.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="32sp"
    android:layout_height="32sp"
    xmlns:tools="http://schemas.android.com/tools">

    <ImageView
        android:id="@+id/img_button"
        android:layout_width="32dp"
        android:layout_height="32dp"
        android:src="@drawable/ic_check_box_outline_blank_black_24dp"/>


    <TextView
        android:id="@+id/tabCount"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:textAlignment="center"
        android:textColor="?attr/textcolor"
        android:textSize="12sp"
        android:textStyle="bold"
        tools:text="1" />
</RelativeLayout>

I had it this way as I wrote it down here and it works for me, but it only shows me the counter and not the icon plus the counter.

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
            menuInflater.inflate(R.menu.tab_menu, menu)

        countButton = menu?.findItem(R.id.tab_list_button)
        countButton?.title = TabInfo.count().toString()  
        countButton?.actionView?.
            setBackgroundResource(R.drawable.ic_check_box_outline_blank_black_24dp)

            return super.onCreateOptionsMenu(menu)
    }

My English is not very good, excuse me. Thanks