Как вернуть результат работы WorkManager в приложение?

You can use Observer on a LiveData<WorkInfo> object or LiveData<List<WorkInfo>> obtained from WorkManager by id or tag. In WorkInfo, there is a field outputData that contains the result.

Example of obtaining LiveData:

// Getting LiveData by id
val workInfoByIdLiveData: LiveData<WorkInfo> =
    WorkManager.getInstance(context).getWorkInfoByIdLiveData(workId)

// Getting LiveData by tag
val workInfoByTagLiveData: LiveData<List<WorkInfo>> =
    WorkManager.getInstance(context).getWorkInfosByTagLiveData(tag)

Example of observing the result:

// Observing LiveData<WorkInfo>
workInfoByIdLiveData.observe(lifecycleOwner, Observer { workInfo ->
    if (workInfo != null && workInfo.state.isFinished) {
        val resultData = workInfo.outputData
        // Process the result from resultData
    }
})

Within Worker, the result is returned using Result.success(Data).

class MyWorker(appContext: Context, workerParams: WorkerParameters):
    Worker(appContext, workerParams) {

    override fun doWork(): Result {
        // Perform background work
        val outputData = Data.Builder()
            .putString("result_key", "Success!")
            .build()
        return Result.success(outputData)
    }
}