How to add a sip interface as an extension to 3cx pbx?

[Cognius]

I created a 3cx pbx using twilio elastic sip trunking. I am trying to achieve a IVR kind of feature by having extensions on the pbx created. I tested using a phone number as an extension and it is working fine. But now I need to add a sip interface (which is also created using twilio programmable voice sip domains) as an extension. I am confused as to how should I achieve this using the 3cx pbx created using twilio elastic sip trunking?

 

[leejor]

In reality, everything is a SIP interface, to 3CX, so your description, of what you are attempting to achieve, lacks a bit of detail, for me, at least. Perhaps you can better describe how this is intended to work.