Conditional Get Ignored With Fetch Api

I am fetching and parsing an RSS feed (https://www.mangaupdates.com/rss.php) with Discord.js/Node.js. I'm currently trying to add a conditional If-Modified-Since header to make a c

Solution 1:

Fetch API replaces 304 with 200 internally even if the requested resource is up to date. There's nothing you can do about it.

Check out Recognize HTTP 304 in service worker / fetch()