title: Can't import module qgis in Python 3.9.2
body: <p>I'm working on Python 3.9.2 and got this</p>
  <blockquote>
  <p>error :No module named qgis</p>
  </blockquote>
  <p>I'm trying to connect to a database and query within it.
  I've seen the code beLow working under python 2. Is there any difference with Python 3?</p>
  <pre><code>[...]
  from qgis.core import *
  import qgis.utils
  
  
  uri.setConnection('{0}'.format(hote_IP), &quot;5432&quot;, '{0}'.format(xxx), '{0}'.format(xxx),'{0}'.format(xxx))    
  db = QSqlDatabase.addDatabase(&quot;QPSQL&quot;)    
  db.setHostName(uri.host())    
  db.setDatabaseName(uri.database())    
  db.setPort(int(uri.port()))    
  db.setUserName(uri.username())    
  db.setPassword(uri.password())
  
  sql = '''select field1, field2 from schema.table'''    
  query = db.exec_(sql)
  print(str(query.value(0))
  </code></pre>