Configure Postman for API key authentications

Open Postman.

Create a project folder under Collections. Select '+' to create a new collection and rename it to a name that defines your project. You can also create folders to group related types of requests (such as certificates or seats) within the collection, by right-clicking the new collection and selecting Add folder.

Select the new collection. Under the Authorization tab, select API key from the Type dropdown 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.

Select Save at top right.