docs: use Xquik API-key header

Author: kriptoburak

README.md

@@ -72,7 +72,7 @@ To bypass authentication, or to emit custom headers on all requests to your remo
 },
 ```
 
-For a Streamable HTTP server that uses a bearer API key, set the token in `env` and force HTTP transport:
+For Xquik's Streamable HTTP server, set the API key in `env` and force HTTP transport:
 
 ```json
 {
@@ -85,10 +85,10 @@ For a Streamable HTTP server that uses a bearer API key, set the token in `env`
         "--transport",
         "http-only",
         "--header",
-        "Authorization:${XQUIK_AUTH_HEADER}"
+        "x-api-key:${XQUIK_API_KEY}"
       ],
       "env": {
-        "XQUIK_AUTH_HEADER": "Bearer <xquik-api-key>"
+        "XQUIK_API_KEY": "<xquik-api-key>"
       }
     }
   }