API keys are unique credentials into Ingrid service. They are used to "connect" to Ingrid service from different platforms. Every key has a specific environment associated with it, thus you must use the dedicated token.
API keys are the same for all Ingrid services (Checkout, Tracking, or Transport Automation). You could easily find the keys in the Ingrid Merchant Platform.
If you don't yet have access to the Ingrid Merchant Platform, ask Iris, Ingrid's AI assistant, in the chat on the Ingrid Help Center.
Mind the environment you're working in - the private keys are different for the stage and production environments.
How to get my API Keys?
Login to:
IMP production site - mad.ingrid.com
IMP stage site - mad-stage.ingrid.com
In the upper right corner of the page (next to the "Change" button) it's placed (i) button - click on it.
Click on the (i) icon, and the window with credentials will appear. The private key and private key (base64) are the needed data.