How do I edit where incoming calls get sent?

Hi All,
I am relatively new to Asterisk and so far have only been dealing with outbound.
I am using Goautodial as my interface.
My problem is that when I call my new inbound SIP trunk the CLI shows that the incoming call from 0712345678 was rejected because it could not find extension 0712345678.
I read the Vicidial managers manual on creating inbounds and groups and DIDs etc. I did all that. I have read quite a few articles on here so far and all of them seem to deal with the next stage of the call. I looked in SIP.conf and extensions.conf and everything looks ok (to my untrained eye).
The DID does not seem to appear as an extension so I made a new phone (extension) with the number 0712345678 in the hopes that once this registered it would have somewhere to send the call but it just says it can’t find the extension.
I would appreciate any help, including even just being told what I should be looking at.
Thank in advance.
Andrew

P.S.
I started thinking it may be my dialplan missing something so I will paste it below:
exten => _1667902945.,1,AGI(agi://127.0.0.1:4577/call_log)
exten => _1667902945.,2,Dial(SIP/${EXTEN:10},30,tTo)
exten => _1667902945.,3,Hangup

Just post Your sip.conf (we need at least the general-section as well as the section for Your sip-trunk) and Your extensions.conf (we will need the contexts defined in sip.conf [general] and in the sip-trunk-section there).
I would expect, that the context You’re sending the incoming calls to is not defined correctly.