Work.kt

internal class HardWorker : Worker() {
    override fun doWork(): Worker.WorkerResult {
        reallyMassiveHeavyLongPLayingWork();
        return Worker.WorkerResult.SUCCESS // or FAILURE, or RETRY if you want to run again
    }
}

fun hardWorkerRunner() {
    val hardWork = OneTimeWorkRequest.Builder(HardWorker::class.java).build()
    WorkManager.getInstance().enqueue(hardWork)
}