Fix env var in README

Author: xOxD

README.md

@@ -98,12 +98,12 @@ Make sure you complete the various fields.
 
 By default, STDIO transport is used.
 
-To configure [SSE](https://modelcontextprotocol.io/specification/2024-11-05/basic/transports#http-with-sse) or [Streamable HTTP](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#streamable-http), set the `MCP_PROTOCOL` environment variable.
+To configure [SSE](https://modelcontextprotocol.io/specification/2024-11-05/basic/transports#http-with-sse) or [Streamable HTTP](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#streamable-http), set the `MCP_TRANSPORT` environment variable.
 
 Example:
 
 ```bash
-MCP_PROTOCOL=streamable-http \
+MCP_TRANSPORT=streamable-http \
 POLYGON_API_KEY=<your_api_key_here> \
 uv run entrypoint.py
 ```