I'm new using the Firebase Cloud Message. I built an IOS app to receive push notifications. The app works fine. I send messages from the Firebase console and they're displayed correctly.
Now I`m trying to build an web api to allow my customer to send the push messages (without accessing the firebase console). Studying the documentation here I realized that I've always to have a "to", meaning a group, topic or device id.
My question is: can I send a message to all devices (like I can do in the console)? I yes, how so?
Thanks in advance!