Not sure what you need. But, from what I understand, if you bought from Steam, you will never need a license key. You just need steam running on that pc. (Refer to this link : https://forums.stardock.com/486311/accounts-and-activation-support-faq#steamkey)
Also note that you can't change from Steam activation method to license key activation method.
Let us know if you need more information.
Stardock Community Assistant