A little help with the google fonts code in wordpress, please?

Hi guys,

Like the title says, I need some help adding another google font in my wordpress theme.

this is how the code looks like:

<?php
$google_api_output='
{
"kind": "webfonts#webfontList",
"items": [
{
"kind": "webfonts#webfont",
"family": "Abel",
"variants": [
"regular"
],
"subsets": [
"latin"
]
},

I need to add Marcellus SC to it and I created a similar code for it and it shows in my option panel, but it not chnging anything on the site.
Can someone help me with a few directions, because I have not idea how to make this work.

Thanks