How to read array with 1 element

[vinifr]

Sorry for the question, but I was not able to figure out. How to read "symbols" ?
This is returning empty:
std::string symbol = result["msg"]["quotes"][0]["symbols"][0].asString();
cout << "symbol: " << symbol << endl;

{
    "msg" : 
    {
        "active" : 76,
        "quotes" : 
        [
            {
                "price" : 
                {
                    "ask" : null,
                    "bid" : 70.0
                },
                "symbols" : 
                [
                    "doEURUSD-202205231059PT1MC095329"
                ]
            },
            {
                "price" : 
                {
                    "ask" : 42.0655,
                    "bid" : 0.10000000000000001
                },
                "symbols" : 
                [
                    "doEURUSD-202205231059PT1MP095329"
                ]
            },
        ],
        "timestamp" : 1653303463000,
        "underlying" : "EURUSD"
    },
    "name" : "instrument-quotes-generated"
}
`