How to pass a variable inside a function?

Question

I am using a API and passing a variable to the API\'s function but its working in this case: curl_init(\'https://www.coinpayments.net/api.php?txid=123456\');

I want to

Answer 1

when i fire above api url using browser it show error

API requests can only be made via POST. For documentation see: https://www.coinpayments.net/apidoc

so you have to pass variable as a post parameter using below code

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "https://www.coinpayments.net/api.php",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "{'txn_id':".$txn_id."}",
  CURLOPT_HTTPHEADER => array(
    "cache-control: no-cache",
    "content-type: application/json"
  ),
));

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

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}
?>

i got response from above url when i use above code

{
   "error": "No HMAC signature sent",
   "result": []
}