i have ubuntu server 18 when i want
sudo bench setup lets-encrypt
got error
Skipping bootstrap because certbot-auto is deprecated on this system.
Your system is not supported by certbot-auto anymore.
Certbot cannot be installed.
the solution
sudo wget https://raw.githubusercontent.com/certbot/certbot/7f0fa18c570942238a7de73ed99945c3710408b4/letsencrypt-auto-source/letsencrypt-auto -O /opt/certbot-auto