Show how to modify google_product_category element in Google Product Feed

functions.php

<?php

add_filter( 'woocommerce_gpf_elements_google', function ( $elements, $general_id, $specific_id ) {
	// Customise/add $elements['google_product_category'] here. e.g.
	// $elements['google_product_category'] = [ 'My actual category' ];
	return $elements;
}, 10, 3 );