Asterisk +a2billing group ring

Hello and thanks for viewing this. Hoping to get a little help here. Usually I am able to hire someone for this…

Basically I am reloading my server and have changed my office number.
Now, I think from what I see I need to change the number in the extensions.conf file

What I recall is the words years ago hard coded.

Can anyone tell me where exactly what conf files I should be adding (or replacing) the old number with the new number in.

And do I also add it to a MySQL table or something…

A point in the right direction is all I really need I will be more than happy to google from that point.

Thank You for ny help you can provide.

Depends on the details of your dialplan. Asterisk is a toolkit for creating PABXes, not a PABX. There is no general answer to your question.