Audio capture using AMS Standard

I'm trying to capture audio from a mic and save on an AMS server running AMS Standard.

I can make a connection without problems with "rtmp://server_name/live", but when I try to start recording audio with

  mic = Microphone.getMicrophone();

  mic.rate = 44;

  mic.gain = 100;

  mic.setSilenceLevel(0);

  try {

        nsPublish = new NetStream(nc);

        nsPublish.addEventListener(NetStatusEvent.NET_STATUS, netStatus);

        nsPublish.attachAudio(mic);

        nsPublish.publish("recordTest", "record");

   } catch(error:Error) {

       setStatus(error.toString());

       return;

   }

I get the following error: Application doesn't have permissions for server-side record/append of streams; access denied to stream recordTest.

Can anyone tell me why and how to fix it?

Thank you!