从哪里获取数据并不重要，你犯了一个愚蠢的错误，数据格式是JSON，但你强行将其转换为原始文本，所以你必须用唯一的结果来替换result.data。

var formdata = new FormData();
formdata.append("stock_symbol", "PPL");

var requestOptions = {
    method: 'POST',
    body: formdata,
    redirect: 'follow'
};

fetch("https://dev-api.sarmaaya.pk/3.0/company_fundamentals.php", requestOptions)
    .then(response => response.text())
    .then(
        result => {
            console.log('result', result) //now works
        }
    )
    .catch(error => console.log('error', error));

字符串
要使request.data工作，必须将response.text()替换为response.json()

var formdata = new FormData();
formdata.append("stock_symbol", "PPL");

var requestOptions = {
    method: 'POST',
    body: formdata,
    redirect: 'follow'
};

fetch("https://dev-api.sarmaaya.pk/3.0/company_fundamentals.php", requestOptions)
    .then(response => response.json())
    .then(
        result => {
            console.log('result', result.data) //now it works
        }
    )
    .catch(error => console.log('error', error));

型