Hello Allan Leslie,
Thank you for posting in the Microsoft Community Forums.
The 20-digit key for Terminal Services activation should be included in the CAL envelope along with the holographic sticker. If you are unable to locate the key, please contact Microsoft customer support for further assistance. They will be able to help you locate the key or provide you with a new one if necessary.
Hope the above information is helpful to you.
If you have any concerns, please feel free to let me know.
Best Regards,
Bblythe Xiao