I want to prefetch (or maybe preload) a JSON file from an URL and use it later on my JS file.

How can I send the file prefetched JSON to the JS file?

Something like:

(on the HTML head)

<link rel="prefetch" href="https://json.file" as="fetch">

(on the JS file)

fetch("the prefetch file above")
  .then((res) => res.json())
  .then((data) => {
  });