var result = UrlFetchApp.fetch('https://suppliers-api.wildberries.ru/public/api/v1/info?quantity=0', options);
var result = JSON.parse(result);
Logger.log(result);
var keys = [];
for(var i = 0;i<result.length;i++)
{
Object.keys(result[i]).forEach(function(key){
if(keys.indexOf(key) == -1)
{
keys.push(key);
}
});
}
console.log(keys);
ReferenceError: XMLHttpRequest is not defined