The expression Keyboard.LastKeyCode will give you the code for that key. So make a interface and let the user press keys.
Store that code a variables, in a dictionary, in an array, in a list .... whats best for you.
Use Local Storage Object.
Keyboard.StringFromKeyCode(Keyboard.LastKeyCode) will give you a key as a string. Use that to show the user what he has pressed.
If you do this, you wil have to use the conditions 'Key code is down', 'On key code pressed' and 'On key code released' solutions, and compare them with you variables.