Parse error: syntax error, unexpected '[' in E:\home\test.com\www\f.php on line 22

<?php
 
$access_id = "значение";
$secret_key = "значение";
$actual_amount = "значение";
$coin_type = "BTC";
$coin_address = "адрес";
 
$params = array(
    "access_id" => $access_id,
    "actual_amount" => $actual_amount,
    "coin_type" => $coin_type,
    "coin_address" => $coin_address,
    "tonce" => round(microtime(true) * 1000),
    "transfer_method" => "onchain",
);
 
print(send_request("https://api.coinex.com/v1/balance/coin/withdraw", $params, get_sign($params, $secret_key)));
 
function get_sign($params, $secret_key){
    ksort($params);
    $pre_sign_ls = [];
    foreach ($params as $key => $val){
        array_push($pre_sign_ls, "$key=$val");
    }
    array_push($pre_sign_ls, "secret_key=$secret_key");
    $pre_sign_str = join("&", $pre_sign_ls);
 
    return strtoupper(md5($pre_sign_str));
}
 
function send_request($url, $params, $sign){
    $headers = [
        'authorization:' . $sign,
        'Content-type: application/json'
    ];
    
    $params = json_encode($params);
    
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $params);
    curl_setopt($ch,CURLOPT_HTTPHEADER, $headers);
    $output = curl_exec($ch);
    return $output;
}