code: def get_iso_time_str(timestamp: Union[int, float, str, datetime]=None) -> str:
      
      if isinstance(timestamp, (int, float)):
          maya_dt = maya.MayaDT(timestamp)
      elif isinstance(timestamp, str):
          maya_dt = maya.when(timestamp)
      elif timestamp is None:
          maya_dt = maya.now()
      else:
          raise ValueError(f'`{type(timestamp)}` is not supported')
      return maya_dt.iso8601()
docs: Get the ISO time string from a timestamp or date obj. Returns current time str if no timestamp is passed