To activate Windows SERVER 2019 Datacenter over the phone:
From the Start screen, type slui to open the Search charm, and then select slui 4 from the search results.
Click the down arrow under Select your country or region, select the name of your country or region, and then click Next.
Call the telephone number provided on the Call and provide your installation ID screen. Be prepared to enter the series of numbers listed under Installation ID.
Follow the instructions from the telephone system. When provided with the confirmation ID, write the numbers down.
On the Call and provide your installation ID screen, click the Enter confirmation ID button.
On the Enter your confirmation ID screen, enter the numbers into fields A through H, in the same sequence as provided by the telephone system, and then click Activate Windows.
Or watch this clip :
https://www.youtube.com/watch?v=3RVzTvpqrYk
activation website :
https://getcid.info
This site will bring you your activation ID
