delete notification channel method

android/src/main/java/com/evollu/react/fcm/FIRMessagingModule.java

@@ -123,6 +123,15 @@ public class FIRMessagingModule extends ReactContextBaseJavaModule implements Li
         promise.resolve(null);
     }
 
+    @ReactMethod
+    public void deleteNotificationChannel(String id, Promise promise) {
+	    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+		    NotificationManager mngr = (NotificationManager) getReactApplicationContext().getSystemService(NOTIFICATION_SERVICE);
+		    mngr.deleteNotificationChannel(id);
+	    }
+	    promise.resolve(null);
+    }
+
     @ReactMethod
     public void getFCMToken(Promise promise) {
         try {

index.js

@@ -96,6 +96,12 @@ FCM.createNotificationChannel = (channel) => {
   }
 }
 
+FCM.deleteNotificationChannel = (channel) => {
+  if (Platform.OS === 'android') {
+    return RNFIRMessaging.deleteNotificationChannel(channel);
+  }
+}
+
 FCM.presentLocalNotification = (details) => {
   details.id = details.id || new Date().getTime().toString();
   details.local_notification = true;