Use a NonceΒΆ

curl -XPOST --data '{"arbitrary": "key value data"}' \
    https://<tenantUrl>/actors/v2/<actorId>/messages?uuid=1073f4ff-c2b9-5190-bd9a-e6a406d9796a&\
    name=finish&token=0dc73dc3ff39b49a&\
    x-nonce=TACC_XXXXxxxxYz