Which answer is correct?

Use `Promise.all(urls.map(url => fetch(url)))` to await all promises at once.

— promise_expert

Add `async` before the `forEach` callback: `urls.forEach(async (url) => { await fetch(url); })`. This makes the callback async.

— async_helper

Use a `for...of` loop instead: `for (const url of urls) { await fetch(url); }`. `forEach` ignores the return value of its callback, so it can't await promises.

— loop_advocate

Use `urls.reduce((p, url) => p.then(() => fetch(url)), Promise.resolve())` for sequential processing.

— fp_enthusiast