Permanently change User-Agent parameter chansip

FreePBX Configuration
1

User-Agent: FPBX-15.8.1(…)
Anyone knows how to permanently change the User-Agent parameter above to eg Quip-PTY? have changed on sip_general_additional.conf and ofcos restarted asterisk,
but anytime you make a small change on freepbx GUI the default useragent parameter restores to default FPBX-15.8.1(…) . Any other way to rectify this ?

2
  1. Stop using chan_sip

2.if you want to make changes use the _custom files

  1. Ask yourself if you really need a different user agent.