This feature is available with the following pricing plans: Premium, Unlimited, Pay as You Grow
This article explains how to locate your API key. Each API key is unique to a specific user (not a school-wide API Key). Ensure the user account from which the API key is pulled is one that will not be deleted moving forward as that will disrupt your API requests. We recommend setting up an account for the developer from your team who's working on this task and have the developer pull the API Key from their account.
Once you have the app enabled, go to the Apps page and click Configure next to API Access.
The API key is provided in the API details section.