为什么我无法获取zebpay Api数据？

I am using these code to fetch zebpay api data. From this API URL - https://www.zebapi.com/api/v1/market/ticker/btc/inr

    function get_api($url){
        if(!empty($url)){
$api_url=$url;
if (@$_GET['curl']=="yes") {
  return(header('HTTP/1.1 503 Service Temporarily Unavailable'));
} else {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $api_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$parsed_json = curl_exec($ch);
$parsed_json = json_decode($parsed_json);
return($parsed_json);
curl_close($ch);
    }
  }
}
$api= get_api('https://www.zebapi.com/api/v1/market/ticker/btc/inr');
echo $api->buy;

I have also try file_get_contents but same problem. I have face this issue in 2 more api's. Note: Once i get the data and use it correctly but today this is not working again.

you can call it directly by curl,

<?php

$getCurrency = "inr";
$displayArrayOutput = true;

$curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => "https://www.zebapi.com/api/v1/market/ticker/btc/inr",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
    if($displayArrayOutput){
        $response = json_decode($response, true);
        echo "<pre>";
        print_r($response);
    }
    else{
        header("Content-type:application/json");
        echo $response;
    }
}

?>