Return JSON with 'redirect_to' when handle_failed_second_factor

lib/two_factor_authentication/controllers/helpers.rb

@@ -20,9 +20,14 @@ module TwoFactorAuthentication
       end
 
       def handle_failed_second_factor(scope)
-        if request.format.present? and request.format.html?
-          session["#{scope}_return_to"] = request.original_fullpath if request.get?
-          redirect_to two_factor_authentication_path_for(scope)
+        if request.format.present?
+          if request.format.html?
+            session["#{scope}_return_to"] = request.original_fullpath if request.get?
+            redirect_to two_factor_authentication_path_for(scope)
+          elsif request.format.json?
+            session["#{scope}_return_to"] = root_path(format: :html)
+            render json: { redirect_to: two_factor_authentication_path_for(scope) }, status: :unauthorized
+          end
         else
           render nothing: true, status: :unauthorized
         end