The Forward command forwards a call by ID to another number while it's still in Ringing state. This command forwards the caller.
You can see how to use this command in a HTTP request and what
HTTP response you will get from the phone system (Figure 1).
Step 1: Make a call between two extensions. Use ListActiveCalls command to find the call ID of the call you want to forward. You can find the CallId in the response, between one of the <CallId></CallId> nodes.
Step 2: Initiate a forwarding using a HTTP request as seen in the picture above. Paste the call ID you found in Step 1 in the CallId parameter of the request.