The Opens API use an unique TOKEN for all services.
If you are already using any Opens Service you can get your TOKEN in your Application, if you is not a Opens user yet you can get your Trial TOKEN in the Q-Manager form.
The TOKEN need be passed in the Request, in the Body as a JSON key named "token" together with others JSON keys for the service you are using or in the Header in the Authorization header.
In the Header:
In the Body