HTTP Error 500 when creating E-Mail Draft with API

HTTP Error 500 when creating E-Mail Draft with API

Hi,
I tried to create an email draft for a ticket using the Zoho Desk API (v1); however, I continuously receive HTTP Error 500: An internal server error occurred while performing this operation. I've tried both curl and Python implementations, but neither works. Accessing the ticket and posting a comment works, so the authorization, ticket_id or org_id should be correct.

I oriented on the examples https://desk.zoho.eu/support/APIDocument.do#Threads_DraftEmailReply for the POST Endpoint: https://desk.zoho.eu/api/v1/tickets/{ticketId}/draftReply

Here's my curl attempt:
 
-H "orgId:<org_id>" \
-H "Authorization:Bearer <token> \
-d '{
"content": "We have escaled the issue. Will update you regarding the progress.",
}'

Am I missing something here?