I fetch an API with the following code, which works like expected, but outputs the whole JSON object. How can I output only the value from answer/sichtbarkeitsindex/value?

This is my code:

function fetchApi() {
    return fetch('https://api.sistrix.com/domain.sichtbarkeitsindex?api_key=myKey&format=json&domain=' + document.URL)
    .then(response => {
        if (!response.ok) {
            return response.text().then(text => {throw new Error(text)});
        }                
        return response.text();
    })

}

return fetchApi()
    .then(intent => seoSpider.data(intent))
    .catch(error => seoSpider.error(error));

And this is the whole response:

[
    {
        "answer": [
            {
                "sichtbarkeitsindex": [
                    {
                        "date": "2024-04-22T00:00:00+02:00",
                        "domain": "example.com",
                        "value": 0.0142
                    }
                ]
            }
        ],
        "credits": [
            {
                "used": 1
            }
        ],
        "info": [
            {
                "country": "de",
                "device": "mobile",
                "domain": "example.com"
            }
        ],
        "method": [
            [
                "domain.sichtbarkeitsindex"
            ]
        ]
    }
]