README.md in omniauth-feishu-0.1.2 vs README.md in omniauth-feishu-0.1.3

@@ -70,14 +70,23 @@
       redirect_to new_user_registration_url
     end
   end
 
   def failure
+    flash[:alert] = request.env["omniauth.error"]
     redirect_to root_path
   end
 end
 ```
 
+Devise will create the following url methods:
+- user_feishu_omniauth_authorize_path
+- user_feishu_omniauth_callback_path
+
+So you may add a button like this:
+```
+<%= link_to "Sign in with feishu", user_feishu_omniauth_authorize_path, class: "btn" %>
+```
 
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at https://github.com/renny-ren/omniauth-feishu.