BackgroundService.kt

// MyStartedService.kt
class MyStartedService: Service() {
    private fun doWork(startId: Int, url: String) {
        // Let's fetch something using the url
        stopSelf(startId)
    }
    override fun (intent: Intent?, flags: Int, startId: Int): Int {
        intent?.getStringExtra("EXTRA_URL")?.let {
            doWork(startId, it)
        }
        return START_REDELIVER_INTENT
    }
    
    override fun onBind(intent: Intent): IBinder? {
        // If we don't need to support binding for the service we return a null IBinder
        return null
    }
}

// MyActivity.kt
class MyActivity: AppCompatActivity() {
    // ...
    lateinit var fetchBt: Button

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.my_activity)
        // ... Complete the activity setup
        fetchBt.setOnClickListener {
            val intent = Intent(this@MyActivity, MyStartedService::class.java).apply {
                putExtra("EXTRA_URL", myUrl)
            }
            startService(intent)
        }
    }
}