Enfold not supporting font-weight 800 in open sans

Hi

Could you please let me know how im suppose to add the support for the extra-bold font weight in open sans. Even if I add:

add_filter( ‘avf_google_heading_font’, ‘avia_add_heading_font’);
function avia_add_heading_font($fonts)
{
$fonts[‘Open Sans’] = ‘Open Sans:400,600,800’;
return $fonts;
}

this still does not work. If i do a code inspect I can see in the head the open sans font still only has 400 ,600 as weight classes

Please can you rectify or guide me how to fix this

thanks