No hashtag search

[dappdev20]

When I search for #bitcoin, it works well.
How can I search no hashtag tweets?
I tried like following.

queries = [""]

queue = asyncio.Queue()

workers_count = 1 # limit concurrency here 2 concurrent requests at time
workers = [asyncio.create_task(worker(queue, api)) for _ in range(workers_count)]
for q in queries:
queue.put_nowait(q)

But the result was nothing.

How to set queries?