If you do not want to use the fonts provided by Fontify and want to revert to the original Shopify theme fonts, you can disable the app by turning off the Fontify app embed in the currently active theme.
Your app is currently working with the Vetro theme
Please go to Online Store → Themes → Edit theme.
In the App embed, turn off the Fontify app embed, then click Save
You'll need a Shopify store to follow these steps. If you're just starting, create your Shopify store first, then come back to this guide.