Add Ububtu font to Enfold for H1, H2, H3, H4, H5 and H6

I have done this and added to Theme Functions (functions.php)

add_filter( ‘avf_google_heading_font’, ‘avia_add_heading_font’);
function avia_add_heading_font($fonts)
{
$fonts[‘Ubuntu’] = ‘Ubuntu:400,700’;
$fonts[‘Gentium’] = ‘Gentium+Book+Basic:400i’;
return $fonts;
}

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

$fonts[‘Ubuntu’] = ‘Ubuntu:400,700’;
$fonts[‘Gentium’] = ‘Gentium+Book+Basic:400i’;
return $fonts;
}

Nothing happens when I go to GENERAL STYLING, the fonts do NOT appear in the lists