My review may take more time
I have figured out one thing so far. If you click on a font in their available fonts catalogue (tiny and hard to read on my screen), you’ll get three options- to use on iPhone, use on computer, or use in editor. It says nothing about iPad, yet that’s what Procreate is designed for. I chose computer, navigated to the Procrete app icon on my iPad, clicked on that, and then it was available in Procreate.
I’ve contacted the developer to ask if there’s a how-to guide, but maybe I’m just missing something here. It seems to work, but I feel like it’s not quite right. I’ll update later, if I can.