I created an automation to create a new freshdesk ticket my ticket is closed.

I have a required dynamic ticket field with Level 1 and Level 2 values. However, some of my Level 1 do not have a  Level 2 set up.

    "custom_fields": {
        "cf_product_selection": "{{ticket.cf_product_selection}}",
        "cf_functional_area": "{{ticket.cf_functional_area}}",

    }

My webhook is failing  "field":"custom_fields.cf_functional_area","message":"It should not be set, as input is not expected"

I tried         "cf_functional_area": "{{ticket.cf_functional_area || ''}}" but it’s still not working.

how can I have it check if the ticket has this field and exclude it from my json?