How to exclude empty tags exporting orders as XML file?

I am using PHP code in the plugin WP ALL EXPORT PRO to filter out specific orders from WooCommerce that contain relevant products with relevant details & options and then export them via XML / FTP to my fulfillment partner.

The values for details & options are different for each product. Therefore I need a code snippet to generally exclude empty tags when exporting in the XML file (Concerning the pink marked area in overview below).

USED CURRENT PHP CODE. THE SECTION //add options to the output IS TO BE CONSIDERED

<?php
    function my_get_order_items( $order_id ) {
        $order = wc_get_order( absint($order_id) ); // Get the WC_Order object
    
        if ( ! is_a($order, 'WC_Order') ) {
            return false; // Exit if not an order
        }
        $order_details = ""; // Initialize variable as string to store order details
    
        // Loop through order items
        foreach ( $order->get_items() as $item ) {
            if ( ! ( strpos($item->get_name(), 'KERAMIKTASSE') !== false
            || strpos($item->get_name(), 'BAUMWOLLTASCHE') !== false
            || strpos($item->get_name(), 'SWEATSHIRT') !== false
            || strpos($item->get_name(), 'HOODIE') !== false
            || strpos($item->get_name(), 'T-SHIRT') !== false ) ) { 
                continue; 
            }
            $product    = $item->get_product(); // Get the product object
            $product_id = $item->get_product_id(); // Get the product object
    
            $order_details .= "**LT**item**GT**";
            $order_details .= "**LT**ID**GT**" . $product->get_sku() . "**LT**/ID**GT**";
            $order_details .= "**LT**produktname**GT**" . $item->get_name() . "**LT**/produktname**GT**";
            $order_details .= "**LT**amount**GT**" . $item->get_quantity() . "**LT**/amount**GT**";
            $order_details .= "**LT**upload**GT**" . maybe_serialize( get_field( 'upload', $product_id ) ) . "**LT**/upload**GT**";
            $order_details .= "**LT**size**GT**" . maybe_serialize( get_field( 'size', $product_id ) ) . "**LT**/size**GT**";
            $order_details .= "**LT**groesse**GT**" . $product->get_attribute('pa_groesse')  . "**LT**/groesse**GT**";
            $order_details .= "**LT**material**GT**" . maybe_serialize( get_field( 'material', $product_id ) ) . "**LT**/material**GT**";
            $order_details .= "**LT**print**GT**" . maybe_serialize( get_field( 'print', $product_id ) ) . "**LT**/print**GT**";
            $order_details .= "**LT**variante**GT**" . maybe_serialize( get_field( 'variante', $product_id ) ) . "**LT**/variante**GT**";
            $order_details .= "**LT**category**GT**" . maybe_serialize( get_field( 'category', $product_id ) ) . "**LT**/category**GT**";
    
            //add options to the output
            $order_details .= "**LT**Options**GT**";
            $order_details .= "**LT**Option**GT****LT**ID**GT**" . maybe_serialize( get_field( 'groupid_115', $product_id ) ) . "**LT**/ID**GT****LT**Value**GT**" . maybe_serialize( get_field( 'value_115', $product_id ) ) . "**LT**/Value**GT****LT**/Option**GT**";
            $order_details .= "**LT**Option**GT****LT**ID**GT**" . maybe_serialize( get_field( 'groupid_117', $product_id ) ) . "**LT**/ID**GT****LT**Value**GT**" . maybe_serialize( get_field( 'value_117', $product_id ) ) . "**LT**/Value**GT****LT**/Option**GT**";
            $order_details .= "**LT**Option**GT****LT**ID**GT**" . maybe_serialize( get_field( 'groupid_118', $product_id ) ) . "**LT**/ID**GT****LT**Value**GT**" . maybe_serialize( get_field( 'value_118', $product_id ) ) . "**LT**/Value**GT****LT**/Option**GT**";
            $order_details .= "**LT**/Options**GT**";
            $order_details .= "**LT**/item**GT**";
        }
        return $order_details;
    }
?>