
**Apache Airflow version**:

master

**What happened**:

https://github.com/apache/airflow/blob/master/airflow/models/baseoperator.py#L356 --> should be timedelta not datetime


airflow/models/baseoperator.py
"""Abstract base class that defines how we get an operator link."""
    operators: ClassVar[List[Type[BaseOperator]]] = []
    """
    This property will be used by Airflow Plugins to find the Operators to which you want
    to assign this Operator Link
    :return: List of Operator classes used by task for which you want to create extra link
    """
    @property
    @abstractmethod
    def name(self) -> str:
        """
        Name of the link. This will be the button name on the task UI.
        :return: link name
        """
    @abstractmethod
    def get_link(self, operator: BaseOperator, dttm: datetime) -> str:
        """
        Link to external system.
        :param operator: airflow operator
        :param dttm: datetime
        :return: link to external system
        """