apt install certbot

#juste le certif
letsencrypt certonly -d exemple.com

#creation du conf dans avalaible
sudo certbot --apache -d example.com

renseigner monsite.conf :
/etc/apache2/sites-available/monsite_ssl.....
SSLCertificateFile /etc/letsencrypt/live/DOMAINE.XXX/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/DOMAINE.XXX/privkey.pem

###########

renouvellement let's encrypt 
===> certbot renew --dry-run (pour voir simulation?)
>> certbot renew  (renouvellement)
####################
modifier adresse mail
>>>>>>>  certbot update_account --email yourname+1@example.com
############

EMBY:
openssl pkcs12 -export -out /etc/ssl/emby/certificate.pfx -inkey /etc/letsencrypt/live/champarnaud.ddns.net/privkey.pem -in /etc/letsencrypt/live/champarnaud.ddns.net/cert.pem -certfile /etc/letsencrypt/live/champarnaud.ddns.net/chain.pem

qbittorrent
you will find key and certificate files in /etc/letsencrypt/live/yourhostname.org. Copy/paste privkey.pem and cert.pem in your qbittorrent-nox web-ui and you are done.