Magic API uses API Keys to identify projects in the system. They are private so you should not share them or publically display them.
To generate an API Key, navigate to your project page. At the top you'll find the API Keys section where you can find the Generate button. Clicking on the button will generate a new API Key assigned to this project.
In order to successfully use the Magic API you need to attach the API Key to each request as part of the headers. It needs to be set as the x-magic-api header like this: