The "Bad Key Header" error may occur for several reasons:
Using an incorrect public key in the request.Solution: Verify that you are using the correct public key.
Sending an API request from an IP address that is not on your account's “White List.”Solution: Add the new IP address to the “White List” and retry the request.
Using an incorrect URL when sending the API request.
Solution: Check the URL to ensure it matches the test or production environment.