After downloading and installing OneSafe software (for instance Driver Manager in the image below) you will be prompted to enter the licence on the first time of use. 

Another way to register the software with the licence bought will be by pressing on the informational "i" symbol, located in the top right corner.

Then press on the text in blue to register the software and enter it when the prompt windows appears. 

Confirm with Activate Now and continue using the software.