How to set a custom referer (referrer) header in a Guzzle request in PHP?

To set a custom referrer header in a Guzzle request in PHP, you can use the Referer header option provided by Guzzle's headers option.

Here's an example of how you can set a custom referrer header in a Guzzle request:

use GuzzleHttp\Client;

// Create a new Guzzle Client instance
$client = new Client();

// Set the request options
$options = [
    'headers' => [
        'Referer' => 'http://example.com', // Set your custom referrer URL here
    ],
];

// Send a GET request with the custom referrer header
$response = $client->get('http://api.example.com', $options);

// Handle the response
echo $response->getBody();

In this example, the custom referrer URL is set as http://example.com. You can set your own custom referrer URL according to your needs.