401 Unauthorized error (HTTP 401)

The request consistently returns a 401 Unauthorized error (HTTP 401).

Full Troubleshooting Report (All n8n Configuration Checks Passed)

Header Name Corrected: The header is set to the case-sensitive format: X-API-KEY.

API Endpoint Corrected: The URL is set to the V1 endpoint: https://api.heygen.com/v1/video/generate.

Key Replacement (Newest Key): I have tried multiple API keys, including a brand new key from a fresh account. The current failing key I am using is:
sk_V2_hgu_kxxfZSeEH63_uq2a30MvrN7ib1RKdHWKtS9Ix46Xlc5E

Authentication Format Confirmed: The key is sent with the mandatory prefix: X-API-KEY: Bearer [Key].

No Conflicts: I have confirmed that no other conflicting authentication headers are being sent (the n8n Authentication field is set to None)