No sip section in extensions.conf

Hi. I’m following this guide to use confernce calls: automated.it/guidetoasterisk.htm
They write that you have to add a new extension at the bottom op the sip section. But i can’t find a sip section in my extensions.conf
Should i make my own sip section?

SIP extensions are set in the sip.conf file.
Usually found in /etc/asterisk