Answer/reject call from key

[w.bogdan]

Would it be possible to use a key (power or volume) to answer or reject a call?
Is there another way to answer a call without using the touchscreen?
Gestures Beta is not working on W10M

 

[w.bogdan]

I've found some registry in HKLM\system\input\Buttons and HKLM\system\input\WEH\Buttons but no documentation for them. Anyone has any idea?