Get the ticket title back from the REST API

Is there a way to get the Zammad title assigned to the ticket, I mean the one with the numbering scheme, from the REST API? When invoklng the add_ticket endpoint I get back only the number attribute.

Are you trying to get the internal ticket ID, the client facing ticket number, or the actual title of the ticket? This reads a bit unclear to me ngl

I would like to get the title of the ticket after the internal id has been placed, so with the value of SystemID.Counter as specified in SettingsTicketTicket Number Format.
I already can get the number from the JSON when listing tickets, but I would like to get the whole ticket subkject as seen within the Zammad UI.

If you already can receive the ticket number (so the number attribtue), then look for the title attribute which holds the complete ticket title. Not always with the ticket number - it depends on the ticket.

In fact, the tickets I create thru the API do not have the title field filled with the information about the numbering. Is there a way to force Zammad to apply the numbering into the ticket and get it back?

No. The ticket number is generated by Zammad during ticket creation - not by you.