Data Format for finetuning Llama2 to extract json

I am trying to finetune Llama 7b on a custom dataset. But I am still confused about the data format for my use case. I want to extract information to json with given keys, which I am providing at the beginning.
The Jumpstart tutorial and the Fine-tune LLaMA 2 (7-70B) on Amazon SageMaker tutorial give the data format of the form:

{"instruction": "","context": "", "response": ""}

The response in my case would be the extracted json.
But where do i give it the sentence to extract the information from, and where to give the json format it should follow and tell it to extract text from this.