Hi.
If you are unable to activate your Windows Server 2019 license using the automated phone activation system, you can try the following steps:
- Open the Command Prompt as an administrator.
- Type "slmgr.vbs /ipk <product key>" and press Enter. Replace "<product key>" with your Windows Server 2019 product key.
- Type "slmgr.vbs /ato" and press Enter to activate your license.
About how to find your Windows product key, please refer to this link: Find your Windows product key - Microsoft Support
Best Regards,
Hania Lian