How to create one of this

How i can create a new buttonKeys using the unity Inspector?

    private void OnEnable()
    {
        buttonKeys = new Dictionary<string, KeyCode>();

        buttonKeys["Up"] = KeyCode.W;
        buttonKeys["Down"] = KeyCode.S;
        buttonKeys["Left"] = KeyCode.A;
        buttonKeys["Right"] = KeyCode.D;
        buttonKeys["Run"] = KeyCode.LeftShift;
        buttonKeys["Jump"] = KeyCode.Space;
        buttonKeys["Crouch"] = KeyCode.LeftControl;
        buttonKeys["Fire1"] = KeyCode.Mouse0;
        buttonKeys["Fire2"] = KeyCode.Mouse1;
        buttonKeys["Use"] = KeyCode.E;
        buttonKeys["Zoom"] = KeyCode.C; //Add one of this. Using the inspector
    }

    Dictionary<string, KeyCode> buttonKeys;

Hi!

To add or edit new controls, you can go to: Edit > Project Settings and select Input category.