openpyxl : I can't open excel file with password

I am a student.

I want to read protected excel file with openpyxl, but I can't.

This is my code.

    wb = load_workbook(file_path)  # Error returned in this line.
    wb.security.workbook_password = 'password'
    ws = wb.active

This is my error message

    Traceback (most recent call last):
  File "D:\env\lib\site-packages\django\core\handlers\exception.py", line 41, in inner
    response = get_response(request)
  File "D:\env\lib\site-packages\django\core\handlers\base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "D:\env\lib\site-packages\django\core\handlers\base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "D:\env\lib\site-packages\django\views\generic\base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "D:\env\lib\site-packages\django\views\generic\base.py", line 88, in dispatch
    return handler(request, *args, **kwargs)
  File "D:\manager\views_payment.py", line 32, in post
    self.read_excel(tmp.payment_excel)
  File "D:\manager\views_payment.py", line 20, in read_excel
    wb = load_workbook(file_path)
  File "D:\env\lib\site-packages\openpyxl\reader\excel.py", line 171, in load_workbook
    archive = _validate_archive(filename)
  File "D:\env\lib\site-packages\openpyxl\reader\excel.py", line 121, in _validate_archive
    archive = ZipFile(f, 'r', ZIP_DEFLATED)
  File "c:\python36\Lib\zipfile.py", line 1100, in __init__
    self._RealGetContents()
  File "c:\python36\Lib\zipfile.py", line 1168, in _RealGetContents
    raise BadZipFile("File is not a zip file")
zipfile.BadZipFile: File is not a zip file

What is the problem?