If your engineering workstation cannot connect to the internet due to corporate security compliance, you can activate the license using an external USB drive:
Ensure the .alf file matches the version of Altium Designer you are trying to activate. altium designer license file download
For computers with temporary internet access, you can download the file directly through the application interface: Altium Designer and open the License Management using your AltiumLive credentials Standalone license from the "Available Licenses" list. Click "Activate" If your engineering workstation cannot connect to the