Hi Patrick,
The version of Photoshop which you have is not clear so you can send us the serial in private message in my inbox & I can look it for you.
However, serial numbers are no longer a concept for Creative Cloud & the subscriptions are now attached to your Adobe ID's (mostly your email ID)
You Can refer to link below to know more into this.
Cloud-based creative software and services | Adobe Creative Cloud
Cheers!
