I finished testing, how do I get an API key for the production environment?

If you are building the API(s) yourself (and not using a plugin solution) you will likely receive a sandbox key first. After succesful testing and confirmation from PostNL's Digitale Klant Support team you will be provided with a production key. Please share with this team a validation set containing at least one succesful API call and response for each webservice and shipping product in scope.