wps_config.xmlfile, which is described on this wiki page. For information on editing other settings and using the admin interface of the WPS, see ConfiguringTheWPS.
/under the name
wps_config.xml. You can either directly edit this file or provide files that should be used instead at build time or at runtime, see https://github.com/52North/WPS#non-default-configuration-file For some background see BestPracticeUserHomeDirConfig.