Visit: https://accounts.rhino3d.com/. You must use your CCC email if you would like to download the software for free or use the software on Azure.
After you have launched Azure, double-click on the Rhino 8 icon to launch the application.
If you see the panel below, click on Skip Registration (blue rectangle at the lower left).
If you see the panel below appear, click on Continue.
If you see the panel below appear, click on Options.
In the menu you should see an option to Login. Proceed with the login to your Rhino account.
The Rhino application should now launch. Check to see that you have full functionality by trying to save a file.