For a deeper look into our Eikon Data API, look into:
Overview | Quickstart | Documentation | Downloads | Tutorials | Articles
Hi @eric.jian,
In general, the learning material within the Eikon Data APIs developer page within the portal should provide you the getting started details. The QuickStart guide outlines details regarding how to create and access an app key.
Within the Eikon search bar, type "app key" and this will pull up your generated app keys.