Claude-API: permission_error

I met the following error:

Traceback (most recent call last):
  File "xx.py", line 156, in <module>
    response = claude_api.send_message(prompt, conversation_id)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\app\miniconda3\Lib\site-packages\claude_api.py", line 130, in send_message
    data = json.loads(json_str)
           ^^^^^^^^^^^^^^^^^^^^
  File "D:\app\miniconda3\Lib\json\__init__.py", line 346, in loads
    return _default_decoder.decode(s)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\app\miniconda3\Lib\json\decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\app\miniconda3\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)

I found that the decoded data_strings is ['{"error": {"type": "permission_error", "message": "We are unable to serve your request"}}'], while i can use the website as usual.