How do i query the Margin calculator API?

I am going through FYERS V3 API. When i try the margin calculator, i get the following response.

```json

{

"s": "error",

"code": -50,

"message": "Please provide valid symbols"

}

```

I am passing the following request to https://api.fyers.in/api/v2/span_margin.

```json

{

"data": [

{

"symbol": "NSE:HDFCBANK-EQ",

"qty": 50,

"side": 1,

"type": 2,

"productType": "CNC"

}

]

}

```

Any suggestions?