The client specified id of the transaction. Object of type string.

The callback address, where the result will be sent when available. Object of type string/uri.

The photo data URI

The verification type

Message authentication code (MAC) to verify the integrity of the message gotten by hashing the data with the client's HMAC secret key.Base 64 encoded string of the SHA256 hash of the request body + API key

Example:
Base64.getEncoder().encodeToString(SHA512(request body + API key))

The Authorization header contains the authentication scheme and a token that authenticates the client to the server

The Accept header is used to specify the media type of the response. The media type is a string of characters that identifies the type of data contained in the response. The media type is used to indicate the type of data that is expected to be returned by the server.