I have done that but its not working I have also tried putting on the number pass throuh on Voiceflex side and now everything is calling from no number
It's in the gateway settings but you need to click on Advanced. This works with Voiceflex, we use it here.
You also need to add the number in the extension in Outbound CalledID Number and Emergency CallerID Number
you are missing something. The caller ID needs to be assigned to the extension and the setting I posted above also has to be added. Restart your gateway after changes and just for good measure, flush the cache