/usr/share/request-tracker4/plugins/ is in rt4-extension-smsnotify 1.04-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/etc/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/etc/initialdata
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Action/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Action/SMSNotify.pm
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Extension/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Extension/SMSNotify/
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Extension/SMSNotify.pm
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Extension/SMSNotify/OnShift.pm
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Extension/SMSNotify/PagerForUser.pm
/usr/share/request-tracker4/plugins/RT-Extension-SMSNotify/lib/RT/Extension/SMSNotify/Shifts.pm