I have an image that I want to preload, that comes from an external source.

That's why I have added the crossorigin="anonymous" attribute.

But now the generated HTML is only the preload without the extra attribute:

<link rel="preload" as="image" href="XXX">

Because of that, Chrome throws following warning in the console:

A preload for 'XXX' is found, but is not used because the request credentials mode does not match.
Consider taking a look at crossorigin attribute.

So the generated HTML should essentially look like this:

<link rel="preload" as="image" href="XXX" crossorigin="anonymous">