Posting unofficial discords are not allowed. See rule S5.2:
5. Do not advertise third-party games, sites, or other places not related to The Powder Toy.
  2. Unauthorized or unofficial community gathering places, such as Discord, are prohibited.

i do plan to make an official one at some point. For now, we don't allow unofficial discords, as they are likely not properly moderated and may be abandoned after a while.