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Download as a Chrome or Desktop application.
Postman lets you define environment variables to easilly abstract your execution contexts.
This is where we'll specify the endpoint and credentials variables required to access your Device.
To create a new environment, click on the Environments options wheel in the upper right corner, and select "Manage environments".
In the "Manage environments" list, click Add to create a new environment.
Fill in the "New Environment Form" with a name ('xAPI - Roomkit' in the example below), and create a first endpoint variable.
Enter the IP address of your device prefixed by 'http://' or 'https://'.
Then add a second variable that will hold the credentials to your device. As xAPI use BasicAuth for authentication, type in the Base64 encoded string of your device username:password.
To assist you in this task, you can use an online service such as https://www.base64encode.org/.
Open the tool, and type username:password in the first text block.
Then click Encode and copy the generated string.
Once done, simply create 'Add', and pick a request among the proposed postman collections.
Make sure that the environment you just created is selected before running the request
Tip: simply create several environments to quickly switch from one Device or Role to another.