Quick and dirty...
python -m venv .venv
./.venv/bin/activate
pip install -r requirements.txt
Copy config.sample.ini to config.ini and edit it.
<IfModule mod_ssl.c>
<VirtualHost *:443>
ServerName postcard.nerdberg.de
Alias /static "/opt/rc3_postcardwall/static"
WSGIDaemonProcess postcard threads=5 python-home=/opt/rc3_postcardwall/venv python-path=/opt/rc3_postcardwall/venv/lib/python3.8/site-packages
WSGIScriptAlias / "/opt/rc3_postcardwall/postcard.wsgi"
<Directory /opt/rc3_postcardwall>
WSGIProcessGroup postcard
WSGIApplicationGroup %{GLOBAL}
Require all granted
</Directory>
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateFile /etc/letsencrypt/live/lists.nerdberg.de/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/lists.nerdberg.de/privkey.pem
</VirtualHost>
</IfModule>
*/2 * * * * PYTHON_HOME=/opt/rc3_postcardwall/venv/lib/python3.10/site-packages/ /opt/rc3_postcardwall/venv/bin/python3 /opt/rc3_postcardwall/imap.py >/dev/null