Edit:

Found the key sequence handling code

  addToKeySequence(t) {
        if (this.keySequence.push(t),
        this.insertCardScreen.createShowDotsAnimation(this.keySequence.length).play(),
        this.keySequence.length < 4)
            this.insertCardScreen.createHideLogosAnimation().play();
        else {
            switch (this.keySequence.join("")) {
            case "1337":
                this.handleWpp();
                break;
            case "4242":
                this.handleInsertCard();
                break;
            default:
                this.handleInvalidCode()
            }
            this.keySequence.length = 0
        }
    }