To access DTS Headphone:X using an included code (for applicable products), open the Microsoft Store. Search for the DTS Sound Unbound application and install (Get) it. Once installed, open it and click on the three dot icon on the top right. In the drop down menu, click on Redeem Code. Follow the on-screen instructions for activation and the license should be activated by the end. Confirm activation within DTS Sound Unbound and DTS Headphone:X should then be available for use.