Cant install fonts Clara BW

Greetings,

I have a problem installing fonts on my new Kobo Clara BW. Previously, on my Kobo Glo HD, I had the Bookerly font (I think I downloaded the one from here in the forums). As far as I remember, it wasn't complicated at all, but now on my new Kobo, I can't get it to detect the fonts no matter what I try. From what I've read, I should put the font family inside the "fonts" folder. I tried copying them directly to the root and also creating a "bookerly" folder, but when I open the font list on the Kobo, they simply don't appear. I tried downloading several fonts, and it doesn't detect any of them—only the ones that come pre-installed show up.

What am I doing wrong? Or what could I be missing?

Thank you very much for your help.