How to provide default values for a string in response ? I am not looking for examples

Need default values for string in response.

For eg: let us say the response schema for 'application/json' content is the below for a 200 GET

ConfigParams:
    type: object
    properties:
        ClientPort:
          type: string

          ##default: how to set ??
        FollowerPort:
          type: string

          ##default:how to set??
        LeaderPort:
          type: string

          ##default:how to set??