missing variables error when entering the json format instructions to the system message

[Kamalsky-dev]

I get error as missing variable error when I enter json format data example in my prompt to the system message. System message can get very specific and different. I just don't understand why json data example returns me error on the system message. I think you should be able to write whatever you want on the system message part. here is the example prompt that gives me error:

Input: "I need black sweater shoes for females with size 48"
Output: {
"type": "sweater shoes",
"brand": null,
"color": "black",
"size": "48",
"gender": "females"
}

Input: "I'm looking for a black shirt unisex size M"
Output: {
"type": "shirt",
"brand": null,
"color": "black",
"size": "M",
"gender": "unisex"
}