API Maintenance Notification issue with a POST call [API, Postman]

Hello,

i have been testing the Maintenance Notification API (Overview | Maintenance Notification | SAP API Business Hub)., for a while in the Postman app.

While the "GET" requests don't cause any issues, even the dreaded CORS for "POST" requests is not problem there is however this issue

When testing the "Maintenance Notification" - "POST" request, i do get the following error:

Question: What to do in situation when the error is "ITAB_LINE_NOT_FOUND" ?

Best Regards,

Roman