Google fonts won't add to child theme via PHP?

I have created a child theme and have placed the following code in my child themes PHP file but the Google font won’t show up in any of the dropdown within the theme?

add_filter( ‘avf_google_heading_font’, ‘avia_add_heading_font’);
function avia_add_heading_font($fonts)
{
$fonts[‘Abril Fatface’] = ‘Abril Fatface’;
return $fonts;
}

add_filter( ‘avf_google_content_font’, ‘avia_add_content_font’);
function avia_add_content_font($fonts)
{

$fonts[‘Abril Fatface’] = ‘Abril Fatface’;
return $fonts;
}