$ python3 manage.py shell
>>> import channels.layers
>>> channel_layer = channels.layers.get_channel_layer()
>>> from asgiref.sync import async_to_sync
>>> async_to_sync(channel_layer.send)('test_channel', {'type': 'hello'})
>>> async_to_sync(channel_layer.receive)('test_channel')
{'type': 'hello'}

Traceback (most recent call last):
  File "<console>", line 3, in <module>
  File "/anaconda3/envs/chatapp/lib/python3.6/site-packages/asgiref/sync.py", line 64, in __call__
    return call_result.result()
  File "/anaconda3/envs/chatapp/lib/python3.6/concurrent/futures/_base.py", line 425, in result
    return self.__get_result()
  File "/anaconda3/envs/chatapp/lib/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/anaconda3/envs/chatapp/lib/python3.6/site-packages/asgiref/sync.py", line 78, in main_wrap
    result = await self.awaitable(*args, **kwargs)
  File "/anaconda3/envs/chatapp/lib/python3.6/site-packages/channels_redis/core.py", line 134, in send
    async with self.connection(index) as connection:
  File "/anaconda3/envs/chatapp/lib/python3.6/site-packages/channels_redis/core.py", line 447, in __aenter__
    self.conn = await aioredis.create_redis(**self.kwargs)
  File "/anaconda3/envs/chatapp/lib/python3.6/site-packages/aioredis/commands/__init__.py", line 177, in create_redis
    loop=loop)
  File "/anaconda3/envs/chatapp/lib/python3.6/site-packages/aioredis/connection.py", line 76, in create_connection
    assert isinstance(address, (tuple, list, str)), "tuple or str expected"
AssertionError: tuple or str expected

asgiref==2.3.2,
channels==2.1.2
Django==2.0.5
Python==3.5+