$gateways_html = ob_get_clean();

		ob_start();
		llms_get_template(
			'checkout/form-summary.php',
			array(
				'coupon'  => false,
				'plan'    => $plan,
				'product' => $plan->get_product(),
			)
		);
		$summary_html = ob_get_clean();

		return array(
			'coupon_html'   => $coupon_html,
			'gateways_html' => $gateways_html,
			'summary_html'  => $summary_html,
		);
	}

	/**
	 * Handle Select2 Search boxes for WordPress Posts by Post Type and Post Status.
	 *
	 * @since 3.0.0
	 * @since 3.32.0 Updated to use llms_filter_input().
	 * @since 3.32.0 Posts can be queried by post status(es) via the `$_POST['post_statuses']`.
	 *               By default only the published posts will be queried.
	 * @since 3.37.2 Posts can be 'filtered' by instructor via the `$_POST['instructor_id']`.
	 * @since 5.5.0 Do not encode quotes when sanitizing search term.
	 * @since 5.9.0 Stop using deprecated `FILTER_SANITIZE_STRING`.
	 *
	 * @return void
	 */
	public static function select2_query_posts() {

		global $wpdb;

		if ( ! is_user_logged_in() ) {
			wp_die();
		}

		// Grab the search term if it exists.
		$term = llms_filter_input_sanitize_string( INPUT_POST, 'term', array( FILTER_FLAG_NO_ENCODE_QUOTES ) );

		// Get the page.
		$page = llms_filter_input( INPUT_POST, 'page', FILTER_SANITIZE_NUMBER_INT );

		// Get post type(s).
		$post_type        = sanitize_text_field( llms_filter_input_sanitize_string( INPUT_POST, 'post_type' ) );
		$post_types_array = explode( ',', $post_type );
		foreach ( $post_types_array as &$str ) {
			$str = "'" . esc_sql( trim( $str ) ) . "'";
		}
		$post_types = implode( ',', $post_types_array );

		// Get post status(es).
		$post_statuses       = llms_filter_input_sanitize_string( INPUT_POST, 'post_statuses' );
		$post_statuses       = empty( $post_statuses ) ? 'publish' : $post_statuses;
		$post_statuses_array = explode( ',', $post_statuses );
		foreach ( $post_statuses_array as &$str ) {
			$str = "'" . esc_sql( trim( $str ) ) . "'";
		}
		$post_statuses = implode( ',', $post_statuses_array );

		// Filter posts (llms posts) by instructor ID.
		$instructor_id = llms_filter_input( INPUT_POST, 'instructor_id', FILTER_SANITIZE_NUMBER_INT );
		if ( ! empty( $instructor_id ) ) {
			$serialized_iid = serialize(
				array(
					'id' => absint( $instructor_id ),
				)
			);
			$serialized_iid = str_replace( array( 'a:1:{', '}' ), '', $serialized_iid );

			$join = $wpdb->prepare(
				" JOIN $wpdb->postmeta AS m ON p.ID = m.post_id AND m.meta_key = '_llms_instructors' AND m.meta_value LIKE %s",
				'%' . $wpdb->esc_like( $serialized_iid ) . '%'
			);
		} else {
			$join = '';
		}

		$limit = 30;
		$start = $limit * $page;

		if ( $term ) {
			$like = " AND post_title LIKE '%s'";
			$vars = array( '%' . $term . '%', $start, $limit );
		} else {
			$like = '';
			$vars = array( $start, $limit );
		}

		// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$posts = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT p.ID as ID, p.post_title as post_title, p.post_type as post_type
			 FROM $wpdb->posts as p
			 $join
			 WHERE p.post_type IN ( $post_types )
			   AND p.post_status IN ( $post_statuses )
			       $like
			 ORDER BY post_title
			 LIMIT %d, %d
			",
				$vars
			) // phpcs:ignore -- The number of params is correct, $vars is an array of two elements.
		);// no-cache ok.
		// phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared

		$items = array();

		$grouping = ( count( $post_types_array ) > 1 );