我正在通過一個拉拉維爾項目來運行這個東西。我已經把頭發扯了一段時間了。到目前為止，我所擁有的是從科因基專業版API文檔中摘錄的。    $request_path = "/orders";    $body = array('size' => $size, 'price' => $eth_price, 'side' => 'sell', 'product_id' => 'ETH-GBP' );    $body = is_array($body) ? json_encode($body) : $body;    $secret = my secret;    $ch = curl_init("https://api.pro.coinbase.com/time");      curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");      curl_setopt($ch,CURLOPT_USERAGENT,'CoinbaseProAPI');      curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);      $result = json_decode(curl_exec($ch));      curl_close($ch);      $timestamp = $result->epoch;      $timestamp_rounded = intval(ceil($timestamp));    $what = $timestamp_rounded.'POST'.$request_path.$body;    $sig =  base64_encode(hash_hmac("sha256", $what, base64_decode($secret), true));    $ch = curl_init("https://api.pro.coinbase.com".$request_path) ;        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true) ;        curl_setopt($ch,CURLOPT_USERAGENT,'CoinbaseProAPI');        curl_setopt($ch, CURLOPT_POST, 1);        curl_setopt($ch, CURLOPT_POSTFIELDS, $body);        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");        curl_setopt($ch, CURLOPT_HTTPHEADER, array(        'CB-ACCESS-KEY: public_key',        'CB-ACCESS-SIGN: '.$sig,        'CB-ACCESS-PASSPHRASE: passphrase',        'CB-ACCESS-TIMESTAMP: '.$timestamp));        $coinbasepro_response = curl_exec($ch) ;        curl_close($ch) ;    dd($coinbasepro_response);我得到的響應是無效的簽名。我很困惑，任何幫助都非常感謝。