Push notifications (XEP-0357) in ejabberd 17.12

Hi,

I understand mod_push was merged into ejabberd 17.12 (https://github.com/processone/ejabberd/pull/1881) but I cannot configure it correctly.

I was going after the instructions at https://github.com/royneary/mod_push but I get an error when trying to call the command "register-push-gcm" with the text "No hook has processed this command".

So, does anyone know if this module is active and usable ? any formal docs on how to configure ?

Thanks,