Welp, I totally misunderstood the question then. Sorry.

Have you tried emailing the authors? It’s well known that some folks will gladly respond with a copy of the paper at no charge.

From the article that was posted:

The main new feature is support for I2P, the Invisble Internet Project. It uses a fully encrypted privacy network layer to hide user activity and locations. The network does not use servers. Peers contributed “a portion of their resources” to other network particpants.

The maintainers promise that “non one can see where traffic is coming from, where it is going, or what the contents are” when the Invisible Internet Project is active.

And to think, I just got downvoted to fuck the other day because someone claimed wasn’t available in the UK. lol

Thank you for clearing that up.

If you’re in the States, maybe take a peek at Firefox Relay.

Yes, it is.

Edit: downvoted because I was able to sign up for a service recently?

Have you tried Firefox Relay? They have a paid tier that gives you a phone number and unlimited email masks. Yes, you have to provide a number, and yes you have to pay, but you wouldn’t be giving Meta or Discord your contact info.