How to send different messages to different devices at once?

[cokemania2]

Whenever a task occurs, I have to send notification of different contents for each user. Now, I'm sending notifications by communicating with each fcm server through for loop, but I wonder if there's a way to send them at once.
Like the send-a-batch-of-message below link
https://firebase.google.com/docs/cloud-messaging/send-message#send-a-batch-of-messages

[Angeloem]

I think am dropping to using the fcm admin sdk... the documentation does not work as expected

[xtrinch]

This is not currently implemented. Feel free to add it with a PR