I put in ...apache2/sites-enabled/000-default.conf
# The ServerName directive sets the request scheme, hostname and port that
# the server uses to identify itself. This is used when creating
# redirection URLs. In the context of virtual hosts, the ServerName
# specifies what hostname must appear in the request's Host: header to
# match this virtual host. For the default virtual host (this file) this
# value is not decisive as it is used as a last resort host regardless.
# However, you must set it for any further virtual host explicitly.
WSGIDaemonProcess proba_wsgi user=proba group=proba maximum-requests=10000
WSGIScriptAlias /proba /home/proba/probaweb/hello.py