To create an API key to enable Push notifications for Android, follow these steps:
1.Go to the pagepage https://console.firebase.google.com.
2.Log in to your Firebase account (tied to the Google account that You registered as a developer in Google Play);
3.Click on the "Add project".
4.Enter a project name, select your country, accept the terms of data protection, confirm the use of the services, Firebase, and then click "Create project";
5.Create a new app on your Android: tap on the icon with the Android logo, in the opened window, enter the package name of the Android package.placeholder (IMPORTANT!) and then click "Register app", download the file "google-services.json" to the computer (need to add in the admin panel), click Next and close the window;
6.Scroll down below, and edit the field "application Alias" and enter there the name of the application "Platform Wide App".
7.Click on Cloud Messaging, where You'll find your "key server" and "sender ID". Copy them (need to add in the admin panel).
8.Go to Backoffice in Nwicode open "Settings"> "Push"> "Configuration" , enter the copied key in the "GCM Key" and the ID of the sender in the "sender ID" - click "Save sender ID and key" and upload the downloaded file "google-services.json".