javascript - 如何获取 Mashape 密钥以使用 Javascript API

Question

    var nRequest = new XMLHttpRequest();
var nutritionalAPIData;
var phrase = document.getElementById('foodSearchBar');
var link = 'https://nutritionix-api.p.mashape.com/v1_1/search/' + phrase + '?fields=item_name%2Citem_id%2Cbrand_name%2Cnf_calories%2Cnf_total_fat';
var mashapeKey = 'My key would be written here';
console.log(link);
JSON.stringify(link);
console.log('Button Works');
    nRequest.open('GET', link);
    nRequest.setRequestHeader('X-APP-KEY', mashapeKey);
    nRequest.setRequestHeader('Content-Type', 'application/json');
    nRequest.onload = function getInfo(){
        nutritionalAPIData = JSON.parse(nRequest.responseText);
        console.log(nutritionalAPIData);
        localStorage.setItem('foodInfo', nutritionalAPIData);
    }
    nRequest.send();

当我发送请求时，谷歌浏览器中的控制台显示我的密钥丢失。我还尝试直接在标题中写入密钥（而不是作为变量），但我遇到了同样的问题。