Lets Encrypt Debian Nginx

Install Certbot

sudo apt install snapd  
sudo snap install core; sudo snap refresh core

remove preinstalled certbot versions

sudo apt-get remove certbot

install certbo

sudo snap install --classic certbot

prepare Certbot command

sudo ln -s /snap/bin/certbot /usr/bin/certbot

Troubleshooting

certbot doesn’t let you choose domain

nginx server proprely configured?
server_name = srv10.kitetrail.net blog.kitetrail.net;