Custom fonts from Adobe Typekit and Google Fonts can be added to the Interface Builder for customers in our Pro and higher plans.
The adoption of a custom font usually involves a code snippet, as in the below from Google Fonts.
First disable the default font as shown below:
Then copy the code provided in the Link area above and place it into the Advanced > Custom Head Tag setting of your Interface as shown below.
Finally, the CSS must be updated to include the following code. Be sure to update the "family" to your selected font. This name is indicated in the Google Font screenshot above as "CSS Rules to specify family"
font-family: "Roboto",Helvetica,Arial,sans-serif !important;
Be sure to save your changes.