Make eircode not optional

I have added code to functions to make the Eircode (zip code) required but when I go to checkout it still says “optional” for eircode. Im not using any checkout field plugins. This is teh code im using:

add_filter( ‘woocommerce_checkout_fields’, ‘make_shipping_eircode_required’, 99 );
function make_shipping_eircode_required( $fields ) {
if ( isset( $fields[‘shipping’][‘shipping_eircode’] ) ) {
$fields[‘shipping’][‘shipping_eircode’][‘required’] = true;
// Optionally update the label to show it’s required.
$fields[‘shipping’][‘shipping_eircode’][‘label’] = __( ‘Eircode *’, ‘your-text-domain’ );
}
return $fields;
}

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