Because file paths on windows use the backslash character as a path separator, and the generateSRIHashesModule function concatenates the path of pages directly as a string in the perPageSriHashes part of the file it generates, the end result contains invalid strings, because the backslashes need to be escaped:

This could be fixed by escaping the paths before concatenating them into the end result, with a function like below. I can submit a PR if you like.

/**
 * @param {string} s 
 * @returns {string}
 */
const escapeJsonString = (s) => {
	if(!s) return s
	const json = JSON.stringify(s)
	return json.substring(1, json.length - 1)
}