Mage2\Checkout\Controllers\CheckoutController::postUser PHP Method

    public function postUser(CheckoutUserRequest $request)
    {
        $orderData = Session::get('order_data');
        $request->merge(['password' => bcrypt($request->get('password'))]);
        $user = User::create($request->all());
        Auth::guard('web')->login($user);
        $orderData['user_id'] = $user->id;
        Session::put('order_data', $orderData);
        return redirect()->route('checkout.step.shipping-address');
    }