In Android, a popup menu is a UI element that displays a list of actions or options when a user triggers it, usually through a long press or a tap on a designated trigger view. Here's how you can implement a popup menu in an Android app using Kotlin:

Define a Trigger View: Choose a view that will trigger the popup menu when clicked or long-pressed. This could be a button, an image, or any other UI element. Create a Menu Resource: Define the menu items you want to display in an XML resource file. For example, create a file named popup_menu.xml in the res/menu directory of your project.

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/menu_option_1"
        android:title="Option 1" />
    <item
        android:id="@+id/menu_option_2"
        android:title="Option 2" />
</menu>

Add the following code in the activity_main.xml file in layout directory. In this layout, we place a Button View component.

 <Button  
        android:id="@+id/button"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:text="Button" />  

In Your Activity or Fragment: In the relevant activity or fragment, associate the trigger view with the popup menu and set up the menu item click listeners.

import android.os.Bundle
import android.view.MenuItem
import android.view.View
import android.widget.PopupMenu
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val button: Button= findViewById(R.id.button) // Replace with your actual view

        triggerView.setOnClickListener { showPopupMenu(triggerView) }
    }

    private fun showPopupMenu(view: View) {
        val popupMenu = PopupMenu(this, view)
        popupMenu.inflate(R.menu.popup_menu) // Inflate the menu resource

        popupMenu.setOnMenuItemClickListener { item: MenuItem ->
            when (item.itemId) {
                R.id.menu_option_1 -> {
                    handleOption1Click()
                    true
                }
                R.id.menu_option_2 -> {
                    handleOption2Click()
                    true
                }
                else -> false
            }
        }

        popupMenu.show()
    }

private fun handleOption1Click() {
    // TODO: Implement your logic for Option 1 click
    // For example, display a toast message
    Toast.makeText(this, "Option 1 clicked", Toast.LENGTH_SHORT).show()
}

private fun handleOption2Click() {
    // TODO: Implement your logic for Option 1 click
    // For example, display a toast message
    Toast.makeText(this, "Option 2 clicked", Toast.LENGTH_SHORT).show()
}
}

In this example, when the triggerView is clicked, the showPopupMenu() function is called. Inside this function, a PopupMenu is created and associated with the trigger view.
The inflate() method is used to populate the popup menu with items from the popup_menu.xml resource. The setOnMenuItemClickListener() method is used to handle the click events for each menu item.

Remember to replace R.id.trigger_view with the actual ID of your trigger view in your layout file.
Make sure you have the necessary resources and dependencies set up in your project's build.gradle file, and adapt the code to your app's specific needs and structure.