You must use the OPeNDAP request interface to get data from the data source.
If you would like to start at the top level of this server, go here: https://gpm1.gesdisc.eosdis.nasa.gov/opendap/hyrax
If you think that the server is broken (that the URL you submitted should have worked), then please contact the OPeNDAP user support coordinator at: support@opendap.org