Configure postman for API key authentication

Create a project folder: Under Collections, click on the + symbol to create a New Collection and rename it to a name that defines your project. You can also choose to create folders to group related types of requests (such as Certificates or Seats) within the collection, by right-clicking on the new collection and selecting Add Folder.

Click on the New Collection and under the Authorization tab, select API key from the Type drop down list. Enter x-api-key as the Key value, and the API key associated to the service user you created earlier within the Value text field.

Click Save.