Started here, however is taking quite long before being able to try PI. Only got a message that credentials are being checked, silent thereafter....start here: https://pixinsight.com/trial/index.html
after your trial is over, you can buy a license here:
PixInsight — Commercial License
PixInsight - Advanced Image Processing. PixInsight is a modular, open-architecture, portable image processing platform available for Linux, macOS and Windows.pixinsight.com
rob