Pinpoint might be using the legacy cloud messaging API for push notification

I am trying to set up push notification for my chime app instance users and as AWS suggest was using Pinpoint to do so. While setting up Pinpoint application, it needs FCM Key API which is the Server Key. But Looks like the FCM API V1 unlike cloud messaging API do not seem to have the server key generated. I am not sure if pinpoint is actually expecting us to still use the legacy API? If not how do I generate the Server Key for the FCM V1 api? I tried using the Web API Key but it sends a 401 Access denied from Firebase server. Any help will be appreciated

Image - https://imgur.com/a/5FpAkuZ