Irrlicht.Net is no longer developed or supported, Irrlicht.Net Cross Platform is a much more complete wrapper. Please ask your C# related questions on their forums first.
in irrlicht.net we have this function
AddCameraSceneNodeFPS(...)
but it's default key for movement are arrow up down right left
-so how to change to 'w' 's' 'a' 'd'
because irrlicht.NET won't have keymap