My Font - Font Installer

So this app is great! It has lots of fonts. I do have one question though, how do you use the fonts, like how do you type with the fonts?

The album will be titled: “I feel as though the fact that the creators of the My Font app felt as if they must restrict it to individuals of at least thirteen years of age in its full title on the App Store, ‘My Font - Install font for 13+,’ when countless other apps exist without such specific disclaimers despite being inherently more complex or requiring greater user responsibility, is, in its absolute entirety, wholly unnecessary, deeply ironic, and, ultimately, pointless.”

Can’t even use the font I selected