This gist is used in the tutorial https://www.vijayan.in/how-to-create-custom-table-list-in-wordpress-admin-page

process_bulk_action.php

<?php
...
	/**
	 * Get bulk actions.
	 *
	 * @return void
	 */
	public function process_bulk_action() {
		if ( 'trash' === $this->current_action() ) {
			$post_ids = filter_input( INPUT_GET, 'draft_id', FILTER_DEFAULT, FILTER_REQUIRE_ARRAY );

			if ( is_array( $post_ids ) ) {
				$post_ids = array_map( 'intval', $post_ids );

				if ( count( $post_ids ) ) {
					array_map( 'wp_trash_post', $post_ids );
				}
			}
		}
	}
  ...