We are experimenting with a few ways to chat. One is google document chat (see the link in the comments below), but we are currently gravitating towards this one on Discord:

https://discord.gg/tGy2pPk

Also, be sure to add this book to your 'private library' so that you get notified when a new chapter is added (each chapter is a new weekly prompt)

(Link posted again below in comments so you can click it)