Adding tags in update tickets API

Hi!

I found in https://developer.zendesk.com/api-reference/ticketing/tickets/tickets/#update-ticket that for handling tags I need to use additional_tags. However it does not seem to work when I'm just updating a single ticket but only when bulk updating tickets. How do I add a tag to single ticket via API? If I use tags, it will replace already existing tags which is not the result I want. If I use additional_tags in my PUT request {{testUrl}}/api/v2/tickets/883 it does nothing.

Br.

Otto