Niantic Campfire app is finally invite only. Why I say finally because if I try to create an account before then you need to use your Google, Apple. Then it says finally that, "We are gradually providing access. In the meantime, the best way to join is being invited by a friend that already has access." It's changed from some time ago where it just said here that, "Niantic Campfire should be available soon," or something like that.
Now it is invite only. If you search over Reddit, you can see that some people already have some access. Users who got access first, you need just to update the app and then you will see this invitation screen that you have been invited. Each user can invite three other users.
How do you receive invitations? You receive invitations via your e-mail. Just you will get some e-mail notifications telling that you got invited to a Niantic Campfire app. Usually, this is the e-mail which is associated with your Pokémon GO e-mail.
Hope this can be helpful. This is just an update. I think the thing is being able to refer other people… Sorry, to invite, to Niantic Campfire. It started to be available from three weeks ago or something like that, 19 days ago when this video is published. Just maybe search for your friends or people who have access to Niantic Campfire or to Pokémon GO community and ask them.No answer to your question? ASK IN FORUM. Subscribe on YouTube!