Ain't working anymore. Here's what the WP debug shows when I try to generate the XML:
[28-Nov-2023 17:34:00 UTC] PHP Deprecated: Automatic conversion of false to array is deprecated in /var/www/site.net/html/wp-content/plugins/adsgooglecatalog/core/includes/products/generalProducts.php on line 0
[28-Nov-2023 17:34:00 UTC] WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')' at line 7 for query
SELECT
google_category_id,
term_id,
identifier_exists,
google_category_text
FROM pre_ads_googlemerchant_category_relation
WHERE term_id IN()
made by do_action('wp_ajax_gmr_ajax'), WP_Hook->do_action, WP_Hook->apply_filters, GMR\core\ajax\request->GMR_ajax, GMR\core\ajax\request->actions, GMR\core\ajax\processXML->handler_addItemsToFile, GMR\core\includes\generationFile\processGeneration->generation, GMR\core\includes\generationFile\processGeneration->getData, GMR\core\includes\generationFile\productData->getPartOfData, GMR\core\includes\generationFile\productData->structureData, GMR\core\includes\generationFile\productData->getCategory, GMR\core\model\views\categories->findCategory
[28-Nov-2023 17:34:00 UTC] PHP Deprecated: Automatic conversion of false to array is deprecated in /var/www/site.net/html/wp-content/plugins/adsgooglecatalog/core/includes/generationFile/productData.php on line 0
Not sure this is only my issue or others, hopefully you'll be able to figure it out if it' a bug.