This webpage provides instructions for using the acme-dns DNS challenge method with various ACME clients to obtain HTTPS certificates for private networks. Caddy, Traefik, cert-manager, acme.sh, LEGO and Certify The Web are listed as ACME clients that support acme-dns. For each client, configuration examples are provided that show how to set API credentials and other settings to use the acme-dns service at https://api.getlocalcert.net/api/v1/acme-dns-compat to obtain certificates. Interesting that so many ACME clients support the acme-dns service, providing an easy way to obtain HTTPS certificates for private networks.
HN https://news.ycombinator.com/item?id=36674224
seiferteric: Proposes an idea for automatically creating trusted certificates for new devices on a private network.
hartmel: Mentions SCEP which allows automatic certificate enrollment for network devices.
mananaysiempre: Thinks using EJBCA for this, as hartmel suggested, adds unnecessary complexity.
8organicbits: Describes a solution using getlocalcert which issues certificates for anonymous domain names.
austin-cheney: Has a solution using TypeScript that checks for existing certificates and creates them if needed, installing them in the OS and browser.
bruce511: Says automating the process is possible.
lolinder: Mentions Caddy will automatically create and manage certificates for local domains.
frfl: Uses Lego to get a Let's Encrypt certificate for a local network website using the DNS challenge.
donselaar: Recommends DANE which works well for private networks without a public CA, but lacks browser support.
Yep, caddy was as easy as to use xcaddy with the module of my DNS, configure the key and run caddy, that's it xD.
For what lolinder mentioned in the news link you need to have port 80 open.
If you don't want that you could configure local authority, but that'll give the warning of a selfsigned certificate.