Preferences DataStore - YouTube Tutorial | https://youtu.be/hEHVn9ATVjY

DataStoreRepository.kt

const val PREFERENCE_NAME = "my_preference"

class DataStoreRepository(context: Context) {

    private object PreferenceKeys {
        val name = preferencesKey<String>("my_name")
    }

    private val dataStore: DataStore<Preferences> = context.createDataStore(
        name = PREFERENCE_NAME
    )

    suspend fun saveToDataStore(name: String){
        dataStore.edit { preference ->
            preference[PreferenceKeys.name] = name
        }
    }

    val readFromDataStore: Flow<String> = dataStore.data
        .catch { exception ->
            if(exception is IOException){
                Log.d("DataStore", exception.message.toString())
                emit(emptyPreferences())
            }else {
                throw exception
            }
        }
        .map { preference ->
            val myName = preference[PreferenceKeys.name] ?: "none"
            myName
        }

}

MainActivity.kt

class MainActivity : AppCompatActivity() {

    private lateinit var mainViewModel: MainViewModel

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

        mainViewModel = ViewModelProvider(this).get(MainViewModel::class.java)
        mainViewModel.readFromDataStore.observe(this, { myName ->
            name_txt.text = myName
        })

        save_btn.setOnClickListener {
            val myName = name_et.text.toString()
            mainViewModel.saveToDataStore(myName)
        }
    }
}

MainViewModel.kt

class MainViewModel(application: Application) : AndroidViewModel(application) {

    private val repository = DataStoreRepository(application)

    val readFromDataStore = repository.readFromDataStore.asLiveData()

    fun saveToDataStore(myName: String) = viewModelScope.launch(Dispatchers.IO) {
        repository.saveToDataStore(myName)
    }
}