After upgrade to webmin 1.940, ssl letsencrypt does not work.
Let's Encrypt is a free, automated, and open certificate authority that can be used to generate an SSL certificate for use by Virtualmin. However, it cannot be used on your system : The Let's Encrypt client command letsencrypt or certbot was not found on your system
On Debian9 the same. But there is no problem to install certbot on D9.
There is no certbot on D8 jessie.
I can't generate certificates now on D8.