To make a request to the Kraken Futures API for the fee schedules and volumes endpoint using PHP, you will need to send an HTTP GET request with the necessary authentication headers. Below, I'll show you how to do this using the `cURL` library.

First, make sure you have a valid API key and secret from your Kraken account, as you'll need these for authentication.

Here’s a PHP example:

```php
<?php

function getKrakenFuturesFeeSchedule($apiKey, $apiSecret) {
// API endpoint
$url = 'https://futures.kraken.com/derivatives/api/v3/feeschedules/volumes';

// Prepare headers for authorization
$headers = [
'Content-Type: application/json',
'API-Key: ' . $apiKey,
'API-Sign: ' . generateAPISignature($url)
];

// Initialize cURL session
$ch = curl_init($url);

// Set cURL options
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // Disable SSL verification for testing (not recommended in production)

// Execute cURL request
$response = curl_exec($ch);

// Check for cURL errors
if ($response === false) {
echo 'Curl error: ' . curl_error($ch);
curl_close($ch);
return null;
}

// Close cURL session
curl_close($ch);

// Return the response
return json_decode($response, true);
}

function generateAPISignature($url) {
// Generate a signature based on your API Secret and other parameters
// You need to implement the appropriate signature logic based on Kraken's API documentation

return base64_encode(hash_hmac('sha256', $url, 'your_api_secret', true));
}

// Replace with your actual API key and secret
$apiKey = 'your_api_key';
$apiSecret = 'your_api_secret';

// Call the function to get the fee schedule
$result = getKrakenFuturesFeeSchedule($apiKey, $apiSecret);

if ($result !== null) {
// Output the result
print_r($result);
} else {
echo "No result returned.";
}

?>
```

### Notes:
1. **API-Sign Calculation**: The `generateAPISignature` function provided is a placeholder. You need to implement the correct hashing method as per Kraken's API requirements. This usually involves creating a nonce, preparing the request data, and using HMAC SHA-512.
2. **SSL Verification**: Disabling SSL verification is not recommended in a production environment. It's used here for simplicity in testing; you should use proper SSL verification in production.
3. **Error Handling**: Ensure you implement better error handling and response validation as needed.

Make sure you replace `your_api_key` and `your_api_secret` with your actual Kraken API key and secret.