The license is a file that you receive by email when you make a purchase. Also a CustomerID is assigned and sent to the email address you registered. So, both your license file and your CustomerID should be in your inbox.
If you loose something (your CustomerID or your license file), the LLBLGen Team can resend it to the registered email address, but, at least you should provide your email address or your Customer ID. To do so please open a new HelpDesk thread (private), as this is a public one.