I just don't know where to put this code. In the page source code? Or is it the CSS?

Thank you so much! For someone like me who only knows as much coding as what I can teach myself on the fly, this is very helpful. A follow-up question - how would you add this in? I tried to convert my working email into HTML, but now I can't switch it back (which is fine, it was just a test email),...

I am trying to add Adobe Fonts from my Creative Cloud to my ACS, but am coming up short when it comes to where I am supposed to put the coding. Does anyone have any additional insight on how I am supposed to do this? Or is there an easier way I'm missing? It seems kind of crazy to me that it would b...