public static function gateways() {
		$id = 'no-gateways';

		if ( ! apply_filters( 'llms_admin_notice_no_payment_gateways', llms()->payment_gateways()->has_gateways( true ) ) ) {
			$html  = __( 'No LifterLMS Payment Gateways are currently enabled. Students will only be able to enroll in courses or memberships with free access plans.', 'lifterlms' ) . '<br><br>';
			$html .= sprintf(
				__( 'For starters you can configure manual payments on the %1$sCheckout Settings tab%2$s. Be sure to check out all the available %3$sLifterLMS Payment Gateways%4$s and install one later so that you can start selling your courses and memberships.', 'lifterlms' ),
				'<a href="' . add_query_arg(
					array(
						'page' => 'llms-settings',
						'tab'  => 'checkout',
					),
					admin_url( 'admin.php' )
				) . '">',
				'</a>',
				'<a href="https://lifterlms.com/product-category/plugins/payment-gateways/" target="_blank">',
				'</a>'
			);
			LLMS_Admin_Notices::add_notice(
				$id,
				$html,
				array(
					'type'             => 'warning',
					'dismiss_for_days' => 730, // @TODO: there should be a "forever" setting here.
					'remindable'       => true,
				)
			);
		} elseif ( LLMS_Admin_Notices::has_notice( $id ) ) {
			LLMS_Admin_Notices::delete_notice( $id );
		}
	}