Hi,
ROK is a product key by OEM, we could contact with them for transfer statement.
Here is a HPE FAQ for Microsoft OEM licensing, please check if it is helpful for you.
HPE FAQ for Microsoft OEM licensing
If any reply is useful for you, please remember to mark it as answer.
Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.
This "Windows Server General Forum" Forum will be migrating to a new home on Microsoft Q&A, please refer to this sticky post for more details.
Bests,