Please check the code snippet below how to enable loudspeaker using Flutter SDK:
//outputs
QBRTCAudioOutputTypes.LOUDSPEAKER
QBRTCAudioOutputTypes.EARSPEAKER
try {
await QB.webrtc.switchAudioOutput(output);
} on PlatformException catch (e) {
//exception
}Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.