How can I sign-up to gateway.auronsoftware.com, so I can use this provider for high-volume SMS?

This is the Auron Test and Demonstration Gateway.

This gateway is for test and demonstration purposes only. With the download the Auron SMS Component or the Auron SMS Server you’ll automatically receive a number of free SMS here.

Use of this gateway is not available commercially.

The purpose of the test and demonstration gateway is to help trial users get started without the need for a subscription to an SMS provider.