config.yml

subdomainOffset: 3  # The number of dot separated parts of host to remove to get to the subdomain(s). For example: 2 would remove example.com from abc.example.com
defaultDestination: &defaultDest http://localhost:8080
proxyRules:  # NOTE: All keys must be lowercase, and ~ means empty. There is no limit to the nesting (at least no limits imposed by the logic of this proxy).
    ~: *defaultDest  # no subdomain
    www: *defaultDest
    https-example: https://localhost:8123
    http-example: http://localhost:3000
    subsubdomain-example:
        ~: http://localhost:3030  # no subsubdomain
        subsubdomain: http://localhost:3031