Display referring affiliate id in a column when visiting shop orders in WP back-end

functions.php

add_filter( 'manage_edit-shop_order_columns', 'custom_shop_order_column', 20 );
function custom_shop_order_column($columns) {
	$reordered_columns = array();

	// Inserting columns to a specific location
	foreach( $columns as $key => $column){
		$reordered_columns[$key] = $column;
		if ( $key == 'order_status' ) {
			// Inserting after "Status" column
			$reordered_columns['my-column1'] = esc_html( 'Referrer' );
		}
	}
	return $reordered_columns;
}

add_action( 'manage_shop_order_posts_custom_column' , 'custom_orders_list_column_content', 20, 2 );
function custom_orders_list_column_content( $column, $post_id ) {
	switch ( $column ) {
		case 'my-column1' :
			if ( class_exists( 'Affiliates_Referral' ) ) {
				$referral_ids = Affiliates_Referral::get_ids_by_reference( $post_id );
				if ( is_array( $referral_ids ) && isset( $referral_ids[0] ) ) {
					$r = new Affiliates_Referral( array( 'referral_id' => $referral_ids[0] ) );
					$referral = $r->read( $referral_ids[0] );
					$affiliate_id = $referral->affiliate_id;
					if ( isset( $affiliate_id ) ) {
						echo esc_html( $affiliate_id );
					}
				}
			}
			break;
	}
}