Firebase messaging, where to get Server Key?

Question

Solution:

1. Click the Settings (Cog wheel) icon next to your project name at the top of the new Firebase Console, as per screenshot below:
2. Click Project settings.
3. Click on the Cloud Messaging tab.
4. The key is right under Server Key.

Take this one: (First answer is right - this one is just to show how the page looks like!) https://support.clevertap.com/docs/android/find-your-fcm-sender-id-and-fcm-server-api-key.html#

UPDATE: As of April 2017 this method does not work. The api_key in google-services.json is only the legacy key. The selected answer is correct.

---

Deprecated way:

In your project there is a JSON file called google-services.json

Open that file and search for

"api_key": [
        {
          "current_key": "********"
        }

those *** are your server api key

If you dont have that file then you can download it from your app details in firebase account

There are two keys on firebase, the first one is in Settings (Tab General) and its call Web API Key.

The second one and in what you are interesting for is in Settings (Tab Cloud Messaging) its called Server key

Use the second one for push notifications from php.