Elementor: Force posts per page number for posts widget on Category Pages

elementor-category-posts-per-page.php

<?php

/**
 * Elementor: Force posts per page number for posts widget on Category Pages
 *
 * @param $query
 */
function elementor_category_posts_per_page( $query ) {

	$category_id_or_slug = 'myslug';
	$posts_per_page = 6;
	if( !is_admin() && $query->is_main_query() && is_category( $category_id_or_slug ) ) {
		$query->set('posts_per_page', $posts_per_page);
	}
}
add_action( 'pre_get_posts', 'elementor_category_posts_per_page' );