title: How to fix the error in python pybliometrics.scopus.exception.Scopus401Error?
body: <p>I'm new to pybliometrics. I opened the python pybliometrics documentation and ran this example:</p>
  <pre><code>from pybliometrics.scopus import AffiliationSearch
  query = &quot;AFFIL(Max Planck Institute for Innovation and Competition Munich)&quot;
  s = AffiliationSearch(query)
  print(s)  
  </code></pre>
  <p>But it throws a pybliometrics.scopus.exception.Scopus401Error error.</p>
  <pre><code>Traceback (most recent call last):
    File &quot;C:/Users/Professional/PycharmProjects/firstScopus/main.py&quot;, line 3, in &lt;module&gt;
      s = AffiliationSearch(query)
    File &quot;C:\Users\Professional\PycharmProjects\firstScopus\venv\lib\site-packages\pybliometrics\scopus\affiliation_search.py&quot;, line 106, in __init__
      Search.__init__(self, query=query, api=&quot;AffiliationSearch&quot;,
    File &quot;C:\Users\Professional\PycharmProjects\firstScopus\venv\lib\site-packages\pybliometrics\scopus\superclasses\search.py&quot;, line 76, in __init__
      Base.__init__(self, qfile, refresh, params=params, url=SEARCH_URL[api],
    File &quot;C:\Users\Professional\PycharmProjects\firstScopus\venv\lib\site-packages\pybliometrics\scopus\superclasses\base.py&quot;, line 70, in __init__
      resp = get_content(url, params, *args, **kwds)
    File &quot;C:\Users\Professional\PycharmProjects\firstScopus\venv\lib\site-packages\pybliometrics\scopus\utils\get_content.py&quot;, line 88, in get_content
      raise errors[resp.status_code](reason)
  pybliometrics.scopus.exception.Scopus401Error
  
  Process finished with exit code 1
  </code></pre>
  <p>As I understand it, I need to specify the API keys. How to do it?</p>