@Vijay_Katoch
This seems to be an issue with access to the download portal. So please contact your organization's system administrator OR raise support with a ticket with us.
Also, the Forms add-on for Mac does not support pdf generation, and we recommend you use either Windows or Linux operating systems to leverage all the features.
Although the Mac OS add-on is only for demo purposes, once you have the access to the portal you can download the software from here - https://experience.adobe.com/#/downloads/content/software-distribution/en/aem.html?package=/content/...
Hope this helps!
