What is a firebase?
Firebase Authentication aims to make building secure authentication systems easy while improving the sign-in and onboarding experience for end users. It provides an end-to-end identity solution, supporting email and password accounts, phone auth, and Google, Twitter, Facebook and more.
below is a URL for the same.
You can create your own firebase account and use the key in CometChat.
Please follow the steps for setting your own Firebase Keys & for further clarification please find the attached screenshot of the same.
Login to your admin panel
Click on "Settings->General" from the left menu.
Search for "Authentication Mode"
Click on "Social Login" Radio Button.
Below Social Login you can see "Advanced Setting".
Configure your Firebase app keys.
Click on Update button