Update chatgpt.mdx

Author: leonardogrig

developer-guides/mcp-setup-guides/chatgpt.mdx

@@ -7,6 +7,10 @@ description: "Add web scraping and search to ChatGPT in 2 minutes"
 MCP support in ChatGPT is currently a beta feature. The interface and availability may change as OpenAI continues development.
 </Note>
 
+<Warning>
+**Availability:** Developer mode with MCP connectors is not available on the Free tier and requires a paid ChatGPT subscription. Availability and features vary by plan and region. See [OpenAI's documentation on Developer Mode](https://help.openai.com/en/articles/12584461-developer-mode-apps-and-full-mcp-connectors-in-chatgpt-beta) for current availability and setup instructions.
+</Warning>
+
 Add web scraping and search capabilities to ChatGPT with Firecrawl MCP.
 
 ## Quick Setup