Resume a conversation by supplying an ID of im or ‘mpim’. Or provide the users field instead.
Return Im?
Boolean, indicates you want the full IM channel definition in the response.
Users
Comma separated lists of user IDs. If only one user is included, this creates a 1:1 DM. The ordering of the users is preserved whenever a multi-person direct message is returned. Supply a channel when not supplying users.