Basic

Authorization: "Basic base64("{appKey}:{secret}")"

Basic authentication is a straightforward scheme in HTTP where a client sends user credentials encoded in Base64 with each request. While easy to implement, it lacks robust security, as credentials can be easily decoded.

You can use your HMAC appKey and secret values as username and password. If you are using a Postman-like client, you can use built-in features, otherwise, you should implement something custom that encodes ${appKey}:${secret} value as base64.