How to add new record to existing collection

I have a collection and my collection has the below format…
“categories”: [
{ “category”: “Pastas”, },
{ “category”: “Pizza Combo”, },
]
Here i would like to add one more category like below…
“categories”: [
{ “category”: “Pastas”, },
{ “category”: “Pizza Combo”, },
{ “category”: “biryani Combo”, },
]
So, How to do this in Dreamfactory ?.