Cost-effective secure Instant Messaging software.
To be able to send messages to mobile client, you will have to register a project with Firebase Console. Here are steps to get Sender Id and API Key.
Go to https://firebase.google.com/. Login with your Google Account (please make sure that you are using the right Google Account as this will be the owner of the project).
1. Click on Create Project button.
2. You will see the following popup, where you can choose the project name.
3. Click on Project settings.
4. Click on Cloud Messaging tab.
5. Copy & paste Sender key and Sender ID to the server's Control Panel.
6. Click Apply to store settings.