[2021] Met my first epic-games cheater today

You can, in fact, report them - you need to report them in the end game and if you have any additional video evidence, you can make a support ticket here: https://support.deadbydaylight.com/hc/en-us/requests/new?ticket_form_id=360000942011 and include the name of the user/gamertag so to speak. It doesn't have to be a Steam ID64, gamertags work too.

It is also what I'm highly suggesting you to do, too, if it happens again.