Kraken Create And Close Position

<?php
namespace ccxt;
include_once (__DIR__.'/../../ccxt.php');
// ----------------------------------------------------------------------------

// PLEASE DO NOT EDIT THIS FILE, IT IS GENERATED AND WILL BE OVERWRITTEN:
// https://github.com/ccxt/ccxt/blob/master/CONTRIBUTING.md#how-to-contribute-code

// -----------------------------------------------------------------------------

error_reporting(E_ALL);
date_default_timezone_set('UTC');

use ccxt\Precise;
use React\Async;
use React\Promise;


// AUTO-TRANSPILE //
var_dump('CCXT Version:', $ccxt->version);


// ------------------------------------------------------------------------------
function example() {
   return Async\async(function () {
       $exchange = new \ccxt\async\kraken(array(
           'apiKey' => 'YOUR_API_KEY',
           'secret' => 'YOUR_API_SECRET',
       ));
       $symbol = 'UNI/USD';
       $side = 'buy'; // set it to 'buy' for a long position, 'sell' for a short position
       $order_type = 'market'; // set it to 'market' or 'limit'
       $amount = 1;
       $leverage = 2;
       Async\await($exchange->load_markets());
       $market = $exchange->market($symbol);
       // if order_type is 'market', then price is not needed
       $price = null;
       // if order_type is 'limit', then set a price at your desired level
       // you can fetch the ticker and update price
       // const ticker = await exchange.fetchTicker (symbol);
       // const last_price = ticker['last'];
       // const ask_price = ticker['ask'];
       // const bid_price = ticker['bid'];
       // if (order_type === 'limit') {
       //     price = (side === 'buy') ? bid_price * 0.95 : ask_price * 1.05; // i.e. 5% from current price
       // }
       $params = array(
           'leverage' => $leverage,
       );
       // log
       var_dump('Going to open a position', 'for', $amount, 'worth', $amount, $market['base'], '~', $market['settle'], 'using', $side, $order_type, 'order (', ($order_type === 'limit' ? $exchange->price_to_precision($symbol, $price) : ''), '), using the following params:');
       var_dump($params);
       var_dump('-----------------------------------------------------------------------');
       try {
           $created_order = Async\await($exchange->create_order($symbol, $order_type, $side, $amount, $price, $params));
           var_dump('Created an order', $created_order);
           // Fetch all your closed orders for this symbol (because we used market order)
           // - use 'fetchClosedOrders' or 'fetchOrders' and filter with 'closed' status
           $all_closed_orders = Async\await($exchange->fetch_closed_orders($symbol));
           var_dump('Fetched all your closed orders for this symbol', $all_closed_orders);
           $all_open_positions = Async\await($exchange->fetch_positions($symbol));
           var_dump('Fetched all your positions for this symbol', $all_open_positions);
       } catch(Exception $e) {
           var_dump(((string) $e));
       }
   }) ();
}


Async\await(example());