Hi I&A Zwijsen,
If you are a Creative Cloud for team user then you need to invite your users to be part of the Team in order to use the product. If you are a Creative Cloud for Enterprise User then you should have recieved a serial no in Licensing.adobe.com. I also would like to inform you that adobe_prtk is only applicable for Creative Cloud Enterprise users as Adobe Provisioning Toolkit Enterprise Edition can be used with serial no only.
I hope it answers your query.
Regards,
Abhijit