I was able to enroll in the ESU for free a few days ago, but I read that they normally charge $30/year for it. I'm not sure what determines if you can get it for free or not.
The option to enroll wasn't visible at first. I had to follow this guide to enable it.
Edit: Make sure you're on Windows 10 ver 22h2 with all the latest patches applied. Also, I'm pretty sure you need to be logged in to Windows using a Microsoft account for the ESU enrollment to work. You can switch back to a local account afterwards.