Added optional two-factor authentication

app/controllers/settings/two_factor_auths_controller.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+class Settings::TwoFactorAuthsController < ApplicationController
+  layout 'auth'
+
+  before_action :authenticate_user!
+
+  def show
+    return unless current_user.otp_required_for_login
+
+    @qrcode = RQRCode::QRCode.new(current_user.otp_provisioning_uri(current_user.email, issuer: Rails.configuration.x.local_domain))
+  end
+
+  def enable
+    current_user.otp_required_for_login = true
+    current_user.otp_secret = User.generate_otp_secret
+    current_user.save!
+
+    redirect_to settings_two_factor_auth_path
+  end
+
+  def disable
+    current_user.otp_required_for_login = false
+    current_user.save!
+
+    redirect_to settings_two_factor_auth_path
+  end
+end