Obtaining Let's Encrypt HTTPS SSL Certificate on Windows

Install the .NET Framework version 4.7.2, and then:

Download ACME Windows Client – WACS

To obtain a certificate, run the WACS.exe with the following arguments:

wacs.exe --target manual --host {DOMAIN_NAME} --webroot {PATH_TO_DOMAIN_ROOT_LIKE_C:\zpanel\panel} --emailaddress {EMAIL_ADDR} --accepttos --validation filesystem --store pemfiles --pemfilespath C:\certs