Because there is no official F998 manufacturer website, follow this :
(On some F998 models)
Do not use random "driver updater" websites. Follow this safe path: f998 sound card software
Many users make the mistake of plugging the F998 into their PC and stopping there. Windows will install a generic USB audio driver, but you will miss the control panel. Follow this guide for full functionality. Because there is no official F998 manufacturer website,