Different account types will have slightly varying views, but to navigate to the API Keys section of your dashboard, you will first need to click 'API Keys' on the navigation menu on the left side of the screen (#1 in the image below). This will then take you to the following screen:
You can generate a set of keys by clicking 'Generate Key' (#2 in the image above) which will pop-up the following confirmation screen:
Click the button to generate a key. Your API Key will be displayed with options to copy the key as well as download the key via a .json file as shown below: