Do I need to specify the certificate hash for push notifications in FCM?

Question

Android

Hello.
There is a topic that I don't understand.

Do I need to enter the hash of the certificate to receive push notifications on android?



I am absolutely sure that Remote config will not work if you do not specify the hash of the certificate.
But I'm not sure about push.

And I still do not understand whether it is necessary to create a channel for each application. Or you can shove a bunch of applications on one channel.

Tell me please.