Hello! I would be really greatful if you can help me with this problem.

I  installed Deepin literally yesterday and that's my first Linux ever, so I'm a complete newbie.
I've got Samsung laptop. On Windows the combination of "Super (looks like Windows icon) + F8" and "Super + F7" adjusted values (higher and lower). And "Super + F6" was to mute.

The thing, those key combos don't work anymore. And interestingly, some (not all of them) other "native" combinations of Super still work - I can turn the touchpad on\off by "Super + F4", adjust brightness by "Super+F3" and "Super + F2".

But I can't adjust sound volume via those combos. I can adjust it from the Dock, yes - but that's not the same. Maybe I need to create some specific shortcut myself? If so - how can I do that? What exactly is the shortcut I need?  

Thank you very much in advance for your help!