What is FCM API key?

With FCM credentials you can set up Web Push Notification service in your site. The API key is stored securely and used by the Push Notifications service to connect to the FCM server and the sender ID (project number) is used by the Android SDK and JS SDK for Google Chrome and Mozilla Firefox on the client side.30 Kas 2016

You can open the project in the firebase , then you should click on the project overview, then goto project settings you will see the web API Key there.2 Ağu 2016

The API key is a unique identifier that authenticates requests associated with your project for usage and billing purposes . You must have at least one API key associated with your project.