There are two options under the Manage API Access page.
API Keys - This table shows all of your generated API keys. Tatango suggests labeling the API keys so it is easy to find the one linked to the external account. This is also a good security practice allowing you to easily disable external access from a compromised system. API Keys can be disabled, as needed.
API Logs - This page shows the details of the last 2 weeks of API calls made to your Tatango account. Clicking on the Method (e.g. subscribers/create) will show the details of that particular API call.
Click on Create API Key to generate a new key.