Before consuming any of the APIs, you will need to authenticate your requests with an API Key. Do do so, you will need to first Sign Up for a free account, you will receive a free API Key to use.
To get your API Key, sign into your account and click the small (i) on the app you wish to consume. A popup like this will appear:
Remember, your API Key is private and should not be shared! You don’t want your key to be abused. Always keep it safe!
To use this key, simply add your key as part of the URL parameters api_key. Additional examples are shown below.