Server api key: migration doc vs migration video

Question

The only change that the GCM -> FCM migration doc requires is changing the endpoint:

Update your server code to use new FCM endpoints for sending messages via HTTP and XMPP... Optionally, you may want to evaluate the FCM HTTP v1 API, which offers an improved security model and new capabilities for customizing messages across

But the video seems to tell a different story:

I'll need to update to a new more secure server key which I can get from the firebase console... download the service account credentials then I'll drag the JSON file into my project... replace the GCM API key with this service account key I'll update my HTTP header to use this access token...

Can we continue to use the GCM server api key when sending requests to the new FCM endpoint or do we "need to update to a more secure server key" obtained from the FCM console?

Answer 1

The GCM documentation you pointed out is kinda (not that much) old. It shows what needs to change when migrating from GCM to FCM Legacy. What Jen Person showed in the video is when you are to use FCM v1 (see the uri on 8:19).

Can we continue to use the GCM server api key when sending requests to the new FCM endpoint or do we "need to update to a more secure server key" obtained from the FCM console?

From my comment here (with minor updates):

Depending on which type of GCM API Key you were using (if this is a reeeaally old project, you might still be using a different type of Key), it may not work. Regardless, after you import your GCM project to Firebase, it would probably generate the necessary API Keys (Server Key for this matter) that you could (and should) use in order for FCM to work.