Sample Request Header

Accept: application/json
Api-Key: fHD30gE4dGLYcj609Dvsi52G9h9fhE7rt90Bd5
Api-User: Yesmail
Content-Type: application/json; charset=utf-8
Connection: keep-alive
If-Match: "dsf53g9eGSD49d34DvQ2Szv"
Note: Incorrect content-types may result in failed requests and an error. Set charset to utf-8 when using unicode characters in your request.

Api-User corresponds to the dbusername defined in your app.