Where in FreePBX do you add new contexts, the stuff that goes into extensions.conf?
I am beginning to suspect so.
Which menu options or modules handle that aspect?
I have gotten round to creating extensions, so which (existing) contexts do I send them to, or how do I modify existing ones ore create new ones?
Have you consulted any of the documentation? If you created extensions in FreePBX you would have seen that you also create inbound and outbound routes based on dialed digits to route traffic to all the features of FreePBX including IVR, ACD’s, Auto Attendant, conference bridge etc.
If you need your own applications to interact with the FreePBX dial plan you need to review the developers documentation and understand the FreePBX generated contexts and how they interface externally.
Typically you try not to have to do that, because it can cause unexpected things to happen, but if there’s no other way around it then the place to put your contexts is extensions_custom.conf. Also pay attention to the “Custom Destinations” and “Custom Extensions” modules (under the Tools tab) as you may need to use one or both of those.
If that is not the way to create them, then where are they setup?
Are users supposed to use the stock contexts that come with asterisk or freepbx and modify them or route them in some way?
It is all new to me.
You don’t get it. When you use FreePBX, you typically do not write your own contexts or make any additions to extensions.conf. That’s the job of FreePBX. If you are reading some book or web page that’s giving you instructions on how to do things in Asterisk, throw it away (not literally, but you get my point) because it’s not at all applicable until you get far beyond the beginner stage. The thing you need to do is force yourself to use the GUI (web interface) and that only. If a book or web site tells you to modify an Asterisk configuration file, pretend they are writing about some piece of software you’ve never heard of and don’t have, because nothing of that is applicable to you at this point.
Books you can read that will be at least somewhat applicable (more or less, depending on how you got FreePBX installed in the first place) are PiaF Without Tears and Elastix Without Tears (Google them, they’re free to download).
Anyway, the rule is you do EVERYTHING from the web interface. That’s the whole point of FreePBX - in theory you should never have to touch an Asterisk configuration file (I say “in theory” because it doesn’t always work that way in practice, but as a beginner you should try to stick to using the GUI only unless you are instructed to do otherwise by a knowledgeable person, or by a book or web site that specifically deals with FreePBX).