Cubit/Bitcoin With curl function

Using Curl same function you have to go the same functionality but here in addition u need to generate nonce and signature. 
To start with bitcoin or cubit you need to generate cubits_key and cubits_secret from your merchant account. To use the cubits api you need three things or All requests to the API MUST include the following headers for authentication:

Cubits-Key: ...
Cubits-Nonce: ...
Cubits-Signature: ...

 here is the code of bitcoin and cubit integration with using curl function 

 <?php

    $url = 'https://api.cubits.com/';
    ini_set('display_errors', 1);
    $name = "test";
    $path = "/api/v1/invoices";
    $url = $url.$path;
    $fields = array(
         
"currency"=>"EUR",
"price"=> "266.45",
"name"=> "shankit sharma",
"description"=> "Twelve ounces of high quality, organic Guatemalan coffee",
"reference"=> "d0cef2"

    );
     $fields = json_encode($fields);
  $_API_KEY = "api key here";
  $_API_SECRET = "api secret here";
    $ch = curl_init();
 
        curl_setopt($ch,CURLOPT_URL,$url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);
        curl_setopt($ch, CURLOPT_POST, 1);
              
                $post_data = hash('sha256',  utf8_encode( $fields ), false );
                $microseconds = sprintf('%0.0f',round(microtime(true) * 1000000));

                $message = utf8_encode($path) . $microseconds . $post_data ;

              
                $hmac_key = $_API_SECRET;
                $signature =hash_hmac("sha512", $message , $hmac_key);
  
     $headers = array('User-Agent: Cubits/PHP v0.0.1');
      $headers[] = "X-Cubits-Key: {$_API_KEY}";
      $headers[] = "X-Cubits-Signature: $signature";
      $headers[] = "X-Cubits-Nonce: $microseconds";
       $headers[] = "Accept: application/vnd.api+json";
       $headers[] = "Content-Type: application/vnd.api+json";
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
//execute post
    $result = curl_exec($ch);
    echo $result;
//close connection
    curl_close($ch);

?>

you will get all your response in result like in which includes invoice id and invoice url. so now you have to redirect the user to that invoice url . when u redirect the user to that url it redirect to cubit/bitcoin payment and that will look like this