Why is my Lookup field not being set through Desk's API?

Why is my Lookup field not being set through Desk's API?

Hello,

I'm having trouble setting a custom field when creating a Ticket in Zoho Desk.

The endpoint I'm consulting is "https://desk.zoho.com/api/v1/tickets" and even though my payload has the right format, with a "cf" key dedicated to all custom fields, there doesn't seem to be a way to make my Lookup field correct.

The lookup points to a Contact in CRM, but sending my 'cf_patient_name' field as the Contact ID I would like my Ticket to be associated with does not accomplish that.

Even worse, the response I get from the API does not contain the same JSON file I sent, which suggests that my field is being ignored.

I tried changing my token's permissions to include the one's needed for searching contacts, but that doesn't work either.

Please take a look at the attachments showing how I send my payload to Zoho (input.json) and what I receive back (output.json). They are just a subset of my real data, so if you think something is missing, it's probably because of that.

Sincerely,

Arthur