post
https://waapi.app/api/v1/instances//client/action/pin-chat
Pins a chat to the top of the chat list. The operation may fail if the maximum number of pinned chats (3) has been reached.
Unauthorized — invalid or missing bearer token
Forbidden — insufficient permissions or account blocked
Not found — instance does not exist or does not belong to you
Conflict — instance is not ready
Too many requests — rate limit exceeded