Update to SDK 27

android/build.gradle

 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "25"
+    compileSdkVersion 27
+    buildToolsVersion "27.0.3"
 
     defaultConfig {
-        minSdkVersion 16
-        targetSdkVersion 23
+        minSdkVersion 19
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
     }
@@ -20,7 +20,7 @@ android {
 
 dependencies {
     // Google's GCM.
-    compile 'com.google.android.gms:play-services-gcm:10.0.1'
+    compile 'com.google.android.gms:play-services-gcm:15.0.1'
 
     compile 'com.facebook.react:react-native:+'
 

android/src/main/java/com/wix/reactnativenotifications/core/notification/PushNotification.java

 package com.wix.reactnativenotifications.core.notification;
 
 import android.app.Notification;
+import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
+import android.os.Build;
 import android.os.Bundle;
 
 import com.facebook.react.bridge.ReactContext;
@@ -136,13 +138,28 @@ public class PushNotification implements IPushNotification {
     }
 
     protected Notification.Builder getNotificationBuilder(PendingIntent intent) {
-        return new Notification.Builder(mContext)
+
+        String CHANNEL_ID = "channel_01";
+        String CHANNEL_NAME = "Channel Name";
+
+        final Notification.Builder notification = new Notification.Builder(mContext)
                 .setContentTitle(mNotificationProps.getTitle())
                 .setContentText(mNotificationProps.getBody())
                 .setSmallIcon(mContext.getApplicationInfo().icon)
                 .setContentIntent(intent)
                 .setDefaults(Notification.DEFAULT_ALL)
                 .setAutoCancel(true);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            NotificationChannel channel = new NotificationChannel(CHANNEL_ID,
+                                                                  CHANNEL_NAME,
+                                                                  NotificationManager.IMPORTANCE_DEFAULT);
+            final NotificationManager notificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);
+            notificationManager.createNotificationChannel(channel);
+            notification.setChannelId(CHANNEL_ID);
+        }
+        
+        return notification;
     }
 
     protected int postNotification(Notification notification, Integer notificationId) {