How do I query (via url) the solr.admin.LukeRequestHandler to get collection index data

I want to use the luke handler as suggested in Solr schema, how to get dynamic fields in a collection, which is http://solr:8983/solr/admin/luke?numTerms=0

but the 4.10.3 solrconfig.xml has the following entry which indicates luke has been rolled into /admin/ and I should be able to use the http://localhost:8983/solr/admin path, which give me a 404 error.

  <requestHandler name="/admin/"
                  class="solr.admin.AdminHandlers" />
  <!-- This single handler is equivalent to the following... -->
  <!--
     <requestHandler name="/admin/luke"       class="solr.admin.LukeRequestHandler" />
     <requestHandler name="/admin/system"     class="solr.admin.SystemInfoHandler" />
     <requestHandler name="/admin/plugins"    class="solr.admin.PluginInfoHandler" />
     <requestHandler name="/admin/threads"    class="solr.admin.ThreadDumpHandler" />
     <requestHandler name="/admin/properties" class="solr.admin.PropertiesRequestHandler" />
     <requestHandler name="/admin/file"       class="solr.admin.ShowFileRequestHandler" >
    -->

When I look for LukeRequestHandler documentation I find http://lucene.apache.org/solr/4_4_0/solr-core/org/apache/solr/handler/admin/LukeRequestHandler.html which expects I am building a java app, which I am not.

I attempt to use several methods found there in a url, all of which 404.

In addition to "how do I query the luke handler to get index data", "is this the correct documentation for what I am trying to figure out?".

Any help in understanding how (these) java docs relate to me trying to understand how Solr works from url would be greatly appreciated.