11. Setting a Request Header

The XHR method to include a header with the request is setRequestHeader. So the full code needs to be:

const searchedForText = 'hippos';
const unsplashRequest = new XMLHttpRequest();

unsplashRequest.open('GET', `https://api.unsplash.com/search/photos?page=1&query=${searchedForText}`);
unsplashRequest.onload = addImage;
unsplashRequest.setRequestHeader('Authorization', 'Client-ID <your-client-id>');
unsplashRequest.send();

function addImage(){
}

Since the New York Times doesn't require a specific header, we don't need to do anything special. We'll set its onload property to the function addArticles that we'll flesh out in a minute:

function addArticles () {}
const articleRequest = new XMLHttpRequest();
articleRequest.onload = addArticles;
articleRequest.open('GET', `http://api.nytimes.com/svc/search/v2/articlesearch.json?q=${searchedForText}&api-key=<your-API-key-goes-here>`);
articleRequest.send();

Make sure to fill in the URL above with the API key you received in an email from the New York Times after signing up as a developer.