* Daten im Body =
:{
::"authentication":::{:::"apiKey": "my_very_secret_api_key",:::"propKey": "secret_key_for_prop_XXXXXX"::},::"bookId": "[BOOKID]",::"invoice":::[:::{::::"description": "Booking.com Provision",::::"status": "",::::"qty": "1",::::"price": "-[COMMISSIONNUM]",::::"vatRate": "7.00",::::"type": "0",::::"invoiceeId": "":::}::]
:}