Smells like you’re not using the API right.
Zammads API is an JSON api which is not reflected by your curl command. Also ensure that you have write permissions on the ticket in question.
A fitting curl command would be:
curl --location --request PUT 'https://example.com//api/v1/tickets/28' \
--header 'Authorization: Bearer <MY TOKEN>' \
--header 'Content-Type: application/json' \
"title": "no help for you"
Technically --data-raw is not necessarily relevant, but that’s what postman generates.