code: def add_issue_comment(self, issue_id_or_key, content, extra_request_params={}):
          
          request_params = extra_request_params
          request_params["content"] = content
          return self.do("POST", "issues/{issue_id_or_key}/comments",
                         url_params={"issue_id_or_key": issue_id_or_key},
                         request_params=request_params,
                         )
docs: client = BacklogClient("your_space_name", "your_api_key")
          client.add_issue_comment("YOUR_PROJECT-999", u"or ... else e.")