Can't link Google fonts in RTP popup

[Some_dude_Sam]

Hello, I'm a new user to Marketo.  We have an Web campaign that is an RTP popup.  I have a Google font (Roboto) linked in the header as per the instructions, but can't get it to reflect.  Anybody familiar with using this or have any ideas of how to use customized fonts for this type of campaign?

Thank you in advance!

-Sam

[Dave_Roberts]

Would it be possible to post a link with the RTP setup? I haven't messed with RTP a whole lot but I'd be happy to hop into the inspector and see if I can identify the issue here if you're able to publish a test page link.