Trouble adding WeChat favicon to the header

Hi!
I know there is another thread that is very similar to this problem, but even after following the steps in there to upload a fontello icon I am unable to select it in the social profiles page to add to my header.

As instructed I have added this code:

// Register new icon as a theme icon
function avia_add_custom_icon($icons) {
	$icons['icon_name']	 = array( 'font' =>'fontello', 'icon' => 'ue800');
	return $icons;
}
add_filter('avf_default_icons','avia_add_custom_icon', 10, 1);

// Add new icon as an option for social icons
function avia_add_custom_social_icon($icons) {
	$icons['Icon Label'] = 'icon_name';
	return $icons;
}
add_filter('avf_social_icons_options','avia_add_custom_social_icon', 10, 1);

but I am not sure what i need to change to specify the WeChat favicon?
Any help is appreciated!