Blocking a Specific Model

Hello,
In the documentation I see an option to block a specific model but, when I try the same Config is not accepting "model" property. Please let me know

This is from Portkey documentation:
For example, if you're using OpenAI and want to block a specific model, your configuration might look like this:

{
"provider": "openai",
"api_key": "your-api-key",
"model": "gpt-4" // Specify only the model(s) you want to use
}