doc: update image refs

en/learn-more/use-cases/connect-dify-to-various-im-platforms-by-using-langbot.mdx

@@ -31,7 +31,7 @@ Fill in your Dify service's API endpoint address, Dify application type, and API
 
 When using workflow applications, please use `summary` as the key to return workflow execution results.
 
-![](https://assets-docs.dify.ai/2025/03/a0359b706a8e7526c12487dc6d78c983.png)
+![](summary_var)
 
 When using workflows, LangBot will explicitly pass the following parameters, which you can add in the start node of your Dify workflow:
 
@@ -42,17 +42,17 @@ When using workflows, LangBot will explicitly pass the following parameters, whi
 
 You can [customize any variables through plugins](https://docs.langbot.app/en/plugin/dev/api-ref.html)
 
-![](https://assets-docs.dify.ai/2025/03/6db041d813987581b27ce434001575bb.png)
+![](input_var)
 
 - For detailed instructions, please refer to the LangBot documentation
 
 ## 4. Demo
 
-> Below shows WeChat and Feishu examples only. Other platforms like QQ, DingTalk, Telegram can also be integrated
+> Below shows Discord and Slack examples only. Other platforms like Lark, DingTalk, Telegram can also be integrated
 
-![](https://assets-docs.dify.ai/2025/03/88bfcb4e72ab852069d49104ad7aa51d.png)
+![](discord_demo)
 
-![](https://assets-docs.dify.ai/2025/03/9682c62f9bcafcffb0b61c2b0f5a6cb1.png)
+![](slack_demo)
 
 {/*
 Contributing Section

zh-hans/learn-more/use-cases/connect-dify-to-various-im-platforms-by-using-langbot.mdx

@@ -31,7 +31,7 @@ LangBot 使用`流水线`控制对消息的处理。首次启动时，LangBot
 
 使用工作流应用时，请使用`summary`作为键传回工作流运行结果。
 
-![](https://assets-docs.dify.ai/2025/03/a0359b706a8e7526c12487dc6d78c983.png)
+![](summary_var)
 
 当使用工作流时，LangBot 会显式传入以下参数，您可以自行在 Dify 工作流的开始节点中添加：
 
@@ -42,7 +42,7 @@ LangBot 使用`流水线`控制对消息的处理。首次启动时，LangBot
 
 您可以[通过插件自定义任何变量](https://docs.langbot.app/zh/plugin/dev/api-ref.html#设置请求变量)
 
-![](https://assets-docs.dify.ai/2025/03/6db041d813987581b27ce434001575bb.png)
+![](input_var)
 
 - 详细的说明请查看 LangBot 文档