This capability is only accesible to Owners or Admins on an account. Account Users will not have access to this function.
Open the Relay app
Under the Group Chat list, tap on the chat you wish to manage
At the top of the screen, you will see the following options:
- Edit Group - add or remove members to the group chat
- Summon Away Devices - bring all devices onto the group chat
- Delete Chat
To add a new chat, please follow the guide here