GCM has limit of 1000 users. What if we need more?

If I understand it correctly, Google Cloud Messaging can only send one message to 1000 different phones. But what if we need to increase this number to 1 million, is that possible ?

I tried to go through the documentation but I did not find anything.

Why do we need GCM?

GCM provides confidentiality and authenticity for the encrypted data and authenticity for the additional authenticated data (AAD). The AAD is not encrypted. GCM mode requires that the IV is a nonce, i.e., the IV must be unique for each execution of the mode under the given key.

What is GCM and how it works?

Google Cloud Messaging functions using server APIs and SDKs, both maintained by Google. The GCM has the ability to send push notifications, deep-linking commands, and application data. Larger messages can be sent with up to 4 KB of payload data.

Is GCM free?

So, it's free.

Is GCM deprecated?

The GCM server and client APIs will be removed on May 29, 2019. GCM will be replaced by Firebase Cloud Messaging (FCM), which will inherit the reliable and scalable GCM infrastructure, plus many new features.

If you need to send the same message to more than 1000 Registration IDs, you simply split the sending process into groups of 1000 Registration IDs. Each group would be sent in a separate request to GCM server.