File: //usr/share/webmin/virtual-server/help/acmes.html
<header>SSL Providers</header>
This page can be used to add ACME-compatible SSL providers for use when
requesting and renewing certificates. When adding a provider you can either
choose one of the services known to Virtualmin, or enter any ACME API URL.
<p>
Some providers require authentication using a key and HMAC, which are typically
available from their website after you create an account. Others allow
certificates to be requested with no authentication. <p>
<footer>