You can find the answers to many questions here, it’s very likely someone before experienced the same problem as you do. Otherwise you can also submit an issue ticket and wait for our help.
You have to register the serial number / license at D16 User Area, it's a place where all our products you purchased are gathered to give you possibility of downloading them anytime you want (for first installation, when update is released, you need to re-install software etc)
Go to https://userarea.d16.pl
If you've received more than one serial number and you've already used one of them to create the User Area account, you may register remaining serials following the procedure below.
If you've had an account at User Area already, the serial number(s) you received have to be added to the existing User Area account, instead of using them to create new account.
The procedure has to be repeated for every serial you've got one by one.