Thanks, it did work for the search icon.
But I tired to replace the Go to top icon but it doesn’t replace it.

// change default icons
add_filter('avf_default_icons','avia_replace_standard_icon', 10, 1);

function avia_replace_standard_icon($icons)
{
$icons['search']	 = array( 'font' =>'myicons', 'icon' => 'ue803'); // works
$icons['up-open']	 = array( 'font' =>'myicons', 'icon' => 'ue801'); // doesn't work
return $icons;
}

Any idea?

Thank you

One more question, if I want to add another path, how I add it?