Hi Tom Lindley1,
firstly, it's important to note that the product key on the label is likely for the physical server itself, not the virtual machines.
To activate the virtual machines, you will need to use a Volume License Key (VLK) or a Multiple Activation Key (MAK) that is associated with your organization's licensing agreement with Microsoft.
If you don't have a VLK or MAK, you can purchase one through the Microsoft Volume Licensing program. Once you have the key, you can use it to activate the virtual machines.
Hope it helps.
Kind regards,
Lei