more like this,
function expandUrl() {
const urlToExpand = url + '?shortUrl=' + $inputField.val() + '&key=' + apiKey;
fetch(urlToExpand).then(response => {
if (response.ok) {
return response.json();
}
}).then(data=>console.log(data));
}
remember that fetch itself returns a promise, and that promise is what you are chaining the .then to