How can I integrate Shopify fonts into a JS web app?

[GergPerson]

Greetings,

I have a little JS web app that lets the user create an image and add some text and then download the image.  There's a dropdown that lets you select the font of the text that you add to the image.  It works locally using Google fonts.  The fonts don't work on Shopify, it tells me to not link to Google fonts.  

How do I get this to work with Shopify fonts?  

Photo example below.  It appears that the text is using the default text of the theme.

Anything helps.  Thanks everyone.

Greg

[miguel_liquify]

@GergPerson can you provide de code?