protected function enableTwoFactor(BackendUser $user, $return)
	{
		// Return if 2FA is enabled already
		if ($user->useTwoFactor)
		{
			return;
		}

		$container = System::getContainer();
		$verifyHelp = $GLOBALS['TL_LANG']['MSC']['twoFactorVerificationHelp'];

		/** @var Authenticator $authenticator */
		$authenticator = $container->get('contao.security.two_factor.authenticator');

		// Validate the verification code
		if (Input::post('FORM_SUBMIT') == 'tl_two_factor')
		{
			if ($authenticator->validateCode($user, Input::post('verify')))
			{
				// Enable 2FA
				$user->useTwoFactor = '1';
				$user->save();

				throw new RedirectResponseException($return);
			}

			$this->Template->error = true;
			$verifyHelp = $GLOBALS['TL_LANG']['ERR']['invalidTwoFactor'];
		}

		// Generate the secret
		if (!$user->secret)
		{
			$user->secret = random_bytes(128);
			$user->save();
		}

		/** @var Request $request */
		$request = $container->get('request_stack')->getCurrentRequest();

		$this->Template->enable = true;
		$this->Template->secret = Base32::encodeUpperUnpadded($user->secret);
		$this->Template->textCode = $GLOBALS['TL_LANG']['MSC']['twoFactorTextCode'];
		$this->Template->qrCode = base64_encode($authenticator->getQrCode($user, $request));
		$this->Template->scan = $GLOBALS['TL_LANG']['MSC']['twoFactorScan'];
		$this->Template->verify = $GLOBALS['TL_LANG']['MSC']['twoFactorVerification'];
		$this->Template->verifyHelp = $verifyHelp;
	}