react-native-android-voice example

index.js

// Import the package
import SpeechAndroid from 'react-native-android-voice';

...
async _buttonClick() {
    try{
        // THIS EASY!
        var spokenText = await SpeechAndroid.startSpeech("Speak into the Mic!", SpeechAndroid.GERMAN);
        ToastAndroid.show(spokenText , ToastAndroid.LONG);
    }catch(error){
        // DO WHATEVER YOU WANT WITH THE PACKAGE ERROR CODES
    }
}
...