Почему выдает ошибку в коде

import requests

url = ' https://api.githup.com/search/repositories?q=language:python&sort=stars '
headers = {'Accept': 'application/vnd.githup.v3+json'}
r = requests.get(url, headers=headers)
print(f"Status code: {r.status_code}")

response_dict = r.json()
print(response_dict.keys())

Результат:
Traceback (most recent call last):
File "C:\Питон\venv\Lib\site-packages\requests\models.py", line 974, in json
return complexjson.loads(self.text, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Ruslan\AppData\Local\Programs\Python\Python311\Lib\json\__init__.py", line 346, in loads
return _default_decoder.decode(s)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Ruslan\AppData\Local\Programs\Python\Python311\Lib\json\decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Ruslan\AppData\Local\Programs\Python\Python311\Lib\json\decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\Питон\Python\main2.py", line 8, in <module>
response_dict = r.json()
^^^^^^^^
File "C:\Питон\venv\Lib\site-packages\requests\models.py", line 978, in json
raise RequestsJSONDecodeError(e.msg, e.doc, e.pos)
requests.exceptions.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
Status code: 200