call this api: DELETE /v3/conversations/{conversationId}/members/{memberId}
return: "message": "The requested resource does not support http method 'DELETE'."
call this api: DELETE /v3/conversations/{conversationId}/members/{memberId}
return: "message": "The requested resource does not support http method 'DELETE'."
As the error suggests, it is not supported. Unfortunately, there isn't anything that you can do to force the call to be accepted if the connected service doesn't support it.
As noted under Conversation operations: