Add WPML Language

wpml-compat.php

public function add_lang_facet( $formatted_data, $raw_data, $object_id ) {
		//wpml compatibility check
		$args     = [ 'element_id' => $object_id, 'element_type' => 'post_id' ];
		$language = apply_filters( 'wpml_element_language_code', null, $args );
		if ( $language !== null ) {
			$formatted_data['lang_attribute_filter'] = [ $language ];
		}
		return $formatted_data;
	}