If you can’t do it from your instance page, open a tab on your browser and search for a font replacer. After you find one, type in what you want, pick a font, copy it, and then paste it to your screen name on your instance under your settings.

There are a lot of options :)

Some letters from some fronts may not properly show up on certain themes, though.

Thank you! Anyone can change their display name in the website and use fancy text!