If you are looking to create your own API key, navigate to My Account --> Settings on your Dashboard:

and find it under the API key click on "Create now":

An API keys window will open up, here click on +Create new:

You will be presented with your new unique API key:

To close the window, you must first check the "I have saved the above secret keys" and then click Close.

You can see if your key is ENABLED/DISABLED, edit the API key, or delete it if you see fit.

If you wish to enable/disable it, click on the "edit key" option.

You can create as many API keys as you like.