Guide for Plot version 1.15.4 and newer:

Add QuickSync to receive your notifications immediately. Starting from 1.15.4 it uses Firebase Messaging. This guide assumes you’ve integrated Plot using Cocoapods. Make sure you already have integrated Plot using the iOS integration guide.
STEP 1: Add To Podfile

Add “pod ‘Firebase/Messaging’, ‘3.16.0’” to your Podfile.

pod 'Firebase/Messaging', '3.16.0'

STEP 2: Add didReceiveRemoteNotification method

Copy the following snippet into your AppDelegate:

-(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
    [Plot didReceiveRemoteNotification:userInfo fetchCompletionHandler:completionHandler];
}

Note: When you use other Firebase functionality in your code, you have to call [FIRApp configure] before calling [Plot initialize…]

Setting up Firebase:

STEP 1: Setup a Firebase Project

Follow the steps at the Firebase Console to setup your project and make sure you enable cloud messaging for your project.

STEP 2: Add Config File

To obtain the GoogleService-Info.plist config file, add your iOS app to Firebase by clicking on the "Add Firebase to your iOS app" and following the instructions.

 In case your Firebase project already has the iOS app, go to the General tab in the Project Settings page and retrieve the config file, as shown in the image below.

Once the GoogleService-Info.plist config is downloaded, add it to your project root.

STEP 3: Almost Done!

After performing the steps above, in order to get the server key, click the settings button, highlighted in red, followed by Project Settings.

Then look up the Legacy server key found in the Cloud Messaging tab, as presented below.

Add that code to the dashboard in the Developer Tools page.

You are now ready to receive your first notification through QuickSync!For more details, look at the extensive documentation.