Platform method channel implementation throws unimplemented error - flutter

Question

I am writing code to wake the screen when a timer runs out. For the timer I am using the android alarm package. To wake the screen, I decided to write some native code in Kotlin. The problem is I am getting unimplemented method error.
Here is my dart code to invoke kotlin code
//Create a platform channel
static const MethodChannel platformChannel = MethodChannel("zeit/wake");
//Function invoking platform code
static void wakeTheScreen() async {
//Invoke platform method
final String result = await platformChannel.invokeMethod("wake");
print(result);
}
Here is my Kotlin code (MainActivity.kt) to wake the screen, but for now it just returns a string by design.
class MainActivity: FlutterActivity() {
private val screenWake = "zeit/wake";
private lateinit var channel: MethodChannel;
//Used for plugins
override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
//Provides automatic registration
super.configureFlutterEngine(flutterEngine)
GeneratedPluginRegistrant.registerWith(flutterEngine)
//Create method Channel with messanger and channel name
channel = MethodChannel(flutterEngine.dartExecutor.binaryMessenger, screenWake)
//Handle calls from flutter for various methods via the channel
channel.setMethodCallHandler { call, result ->
if(call.method=="wake"){
print("ran")
val res = "Turned on"
result.success(res)
}
}
}
}
The code doesn't work, it just gives me this error
Unhandled Exception: MissingPluginException(No implementation found for method wake on channel zeit/wake)
I have tried:
-Hot restart and hot reload
-Stopping app entirely and starting it again
-Stopping app, flutter clean, flutter run
-Changing activity name in android manifest but i reverted as it didn't work.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.zeitb"
android:versionCode="1"
android:versionName="1.0.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="31" />
<!--
The INTERNET permission is required for development. Specifically,
the Flutter tool needs it to communicate with the running application
to allow setting breakpoints, to provide hot reload, etc.
-->
<uses-permission android:name="android.permission.INTERNET" />
<!-- Required Permissions -->
<uses-permission android:name="android.permission.ACCESS_NOTIFICATION_POLICY" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.WAKE_LOCK" /> <!-- For apps with targetSDK=31 (Android 12) -->
<uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM" /> <!-- More Specifications for android alarm manager -->
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.USE_FULL_SCREEN_INTENT" />
<uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
<application
android:name="android.app.Application"
android:appComponentFactory="androidx.core.app.CoreComponentFactory"
android:debuggable="true"
android:icon="#mipmap/ic_launcher"
android:label="Zeit" >
<activity
android:name="com.example.zeitb.MainActivity"
android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
android:exported="true"
android:hardwareAccelerated="true"
android:launchMode="singleTop"
android:screenOrientation="portrait"
android:showWhenLocked="true"
android:theme="#style/LaunchTheme"
android:turnScreenOn="true"
android:windowSoftInputMode="adjustResize" >
<!--
Specifies an Android theme to apply to this Activity as soon as
the Android process has started. This theme is visible to the user
while the Flutter UI initializes. After that, this theme continues
to determine the Window background behind the Flutter UI.
-->
<meta-data
android:name="io.flutter.embedding.android.NormalTheme"
android:resource="#style/NormalTheme" />
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!--
Don't delete the meta-data below.
This is used by the Flutter tool to generate GeneratedPluginRegistrant.java
-->
<meta-data
android:name="flutterEmbedding"
android:value="2" />
<service
android:name="dev.fluttercommunity.plus.androidalarmmanager.AlarmService"
android:exported="false"
android:permission="android.permission.BIND_JOB_SERVICE" />
<receiver
android:name="dev.fluttercommunity.plus.androidalarmmanager.AlarmBroadcastReceiver"
android:exported="false" />
<receiver
android:name="dev.fluttercommunity.plus.androidalarmmanager.RebootBroadcastReceiver"
android:enabled="false"
android:exported="false" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<receiver
android:name="com.dexterous.flutterlocalnotifications.ActionBroadcastReceiver"
android:exported="false" />
<receiver
android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver"
android:exported="false" />
<receiver
android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver"
android:exported="false" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
<action android:name="android.intent.action.QUICKBOOT_POWERON" />
<action android:name="com.htc.intent.action.QUICKBOOT_POWERON" />
</intent-filter>
</receiver>
<uses-library
android:name="androidx.window.extensions"
android:required="false" />
<uses-library
android:name="androidx.window.sidecar"
android:required="false" />
</application>
</manifest>
What could I be doing wrong? What fix have I not tried? Is there a change I should make in the manifest?