After creating the project, you will find MainActivity, but here we have renamed it as HomeActivity.kt, and the layout name is activity_home.

Now go to the activity, and here is the default code for this class:

class HomeActivity : AppCompatActivity() {

 override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main2)
        setSupportActionBar(toolbar)

        fab.setOnClickListener { view ->
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                .setAction("Action", null).show()
        }
    }
}