Update openrouter.mdx

Author: kathayl

src/content/docs/ai-gateway/providers/openrouter.mdx

@@ -24,9 +24,8 @@ When making requests to OpenRouter, ensure you have the following:
 
 - Your AI Gateway Account ID.
 - Your AI Gateway gateway name.
-- An active OpenRouter API token.
+- An active OpenRouter API token or a token from the original model provider.
 - The name of the OpenRouter model you want to use.
-- OpenRouter also allows you to bring your own provider keys (BYOK).
 
 ## Examples