The first step in plugin configuration consists in creating a Firebase account (skip to the next step in case you already have one)
Create a new application, so that you can get the parameters required by the plugin.
Go to https://console.firebase.google.com/ and click on the “Create a project” button.
Now give a name to your project by entering it to the related field.
Activate Google Analytics for your Firebase project by enabling the option Enable Google Analytics for this project and click on Create project.
Wait until your project is created then click on Continue.
Now go to Firebase settings and select Project settings like in the image below.
In the tab General > Your project of Firebase settings, you will find the project ID. Copy it…
…and paste it in the field Firebase project ID that you find in the plugin General settings.
Go back to the tab General > Your project where you will find the Web API key. Copy it…
…and paste it in the field Firebase API key that you find in the plugin general settings.
Now go to the section Service accounts of your project and click on Generate new private key. Copy the file content and…
…paste it in the field Firebase Private key that you find in the plugin general settings.
From the next field, Firebase Database Rules, copy the text and…
…go to your project Database.
Click on the button Create database available in Realtime Database.
In the Security rules for Realtime Database, remove the text shown and paste the one you previously copied from Firebase Database Rules. Now click on Enable.
The last step is to publish by clicking on the button Publish that you find in the Database Rules section.