got an AgoraRtcException(20, Make sure you call RtcEngine.initialize first) even after initializing the engine - flutter

Question

trying to make a 1:1 video meeting with agora with flutter and after following the docs i got
AgoraRtcException(20, Make sure you call RtcEngine.initialize first) exception although I am sure I am initializing it first however this the initialize code
void initState() {
super.initState();
setupVideoSDKEngine();
join();
the setupVideoSDKEngine() method code is
Future<void> setupVideoSDKEngine() async {
// retrieve or request camera and microphone permissions
await [Permission.microphone, Permission.camera].request();
//create an instance of the Agora engine
agoraEngine = createAgoraRtcEngine();
await agoraEngine
.initialize(RtcEngineContext(appId: Environment.agoraAppId));
await agoraEngine.enableVideo();
// Register the event handler
agoraEngine.registerEventHandler(
RtcEngineEventHandler(
onJoinChannelSuccess: (RtcConnection connection, int elapsed) {
showMessage(
"Local user uid:${connection.localUid} joined the channel");
setState(() {
_isJoined = true;
});
},
onUserJoined: (RtcConnection connection, int remoteUid, int elapsed) {
showMessage("Remote user uid:$remoteUid joined the channel");
setState(() {
_remoteUid = uid;
player.stop();
customTimer!.resetAndStart();
});
},
onUserOffline: (RtcConnection connection, int remoteUid,
UserOfflineReasonType reason) {
showMessage("Remote user uid:$remoteUid left the channel");
callEnded = true;
setState(() {
_remoteUid = null;
});
print('stats ${reason.name}');
if (!userOffline) {
Future.delayed(Duration(seconds: 1), () => Navigator.pop(context));
}
userOffline = true;
},
),
);
}
I am expecting to join the channel but nothing happens and it throws this error
I tried to delete the app and reinstall it but nothing happens
and got this exception too AgoraRtcException(-17, null)

Answer 1

you can to call this before using any other agora function i.e. You are trying to use agora sdk function without initializing it so here it is
This will be written globally
late final RtcEngineEx _engine;
this will be written in initState
_engine = createAgoraRtcEngineEx();
await _engine.initialize(const RtcEngineContext(
appId: APP_ID,
channelProfile: ChannelProfileType.channelProfileLiveBroadcasting,
));

Answer 2

This piece of advice I'm giving is for the correct usage of async and await keywords.
In your initState() function, you are calling two functions one after another; out of which the first function setupVideoSDKEngine() is an async function, and another function join() chould also be an async because the Agora join channel code returns a Future.
await engine.joinChannel(agoraToken, channelId, '', 0,);
Your code right now does not wait for the engine initialization and starts joining channel. Thus, the error. So you got to await your initialization and then write your join channel code.
For eg.
/* permission stuffs */
await agoraEngine.initialize(RtcEngineContext(appId: Environment.agoraAppId));
/* do event handling tasks */
// Now join the channel.
await engine.joinChannel(agoraToken, channelId, '', 0,);
It is recommended that you put the whole code into one async function.