rror 403 status connecting to

Great Sample!
Everything worked smooth, and I have deployed it to Azure.
But If I want to connect to the MCP server on Azure, I get a

```
405 status sending message to https://app-tmsa3gquic2e2.azurewebsites.net/, will attempt to fall back to legacy SSE
2025-07-12 00:15:44.432 [info] Connection state: Error 403 status connecting to https://app-tmsa3gquic2e2.azurewebsites.net/ as SSE: You do not have permission to view this directory or page.
```

Locally everything runs well. I get neither the redirect to legacy SSE, nor the following 403.

Any idea what I have missed?
Thanks