The thing that previously presumably hindered this was that the VAPID
keys had to be set up. Previously admins had to do this, but this is a bad
idea for multiple reasons:
1) The meaning of "public key" and "private key" was not well documented
in the settings.
2) Giving out a private key over the API, even just for admins, sounds
like a bad idea.
Co-authored-by: Francis Dinh <normandy@biribiri.dev>