Additional google fonts

Hey! I have added the following code to function.php but i still cant see the fonts.
What i am doing wrong?

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[‘Playfair Display’] = ‘Playfair Display:900’;
return $fonts;
}