Adding Google Font after theme update

I’m not using a Child Theme, and want to add a custom Google Font. Since your new update, the functions.php file has moved and changed. Can you tell me where I can put this code below in the new functions.php file, and where the file is in the new directory structure? Also, is this still the correct code to use?

add_filter( ‘avf_google_heading_font’, ‘avia_add_heading_font’);
function avia_add_heading_font($fonts)
{
$fonts[‘PT Sans Narrow’] = ‘PT Sans Narrow:400,700’;
$fonts[‘PT Sans’] = ‘PT Sans:400,700,400italic,700italic’;
return $fonts;
}

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

$fonts[‘PT Sans’] = ‘PT Sans:400,700,400italic,700italic’;
$fonts[‘PT Sans Narrow’] = ‘PT Sans Narrow:400,700’;
return $fonts;
}