Action bar Back button not working

Question

with the help of these Android Docs.I am trying to do a action bar Back button.I get an Action Bar Back Button like these below image:

Answer 1

if the home button is shown. you should add an action to the home button through onOptionItemSelected fun (arrow in your case) by default there's no action. so it's totally normal that it's not working. Please add this fun to your activity :

 override fun onOptionsItemSelected(item: MenuItem): Boolean {
        return when {
            item.itemId == android.R.id.home -> {
                finish()
                true
            }
            else -> super.onOptionsItemSelected(item)
        }
    }