Use the command crontab -e to edit the crontab (recurring tasks), and insert the following line:

0 0 1 * * /usr/bin/certbot renew --pre-hook “service nginx stop” --post-hook “service nginx start” --quiet > /etc/letsencrypt/renewals.log

It will renew all the certificates, the 1st of each month (0 0 1 * *), and will stop nginx before the renewal and start nginx after the renewal so it can works.
It will work on all the linux servers.