Cryptography Headers in Cryptographic Libraries
What associated data (or encrypted header in the plaintext message) to use is dependent on the protocol, not on the cryptographic algorithm.

Generally, for messages in a transport protocol, you'd use the to avoid replay attacks.

The header data may also contain other meta-data that you want to authenticate for the message.

Beyond that, there is nothing to tell you, because you've only listed a (partial) algorithm, and not the protocol.