Hello,

Sharing how to send an API request using PHP Curl and Bearer token:

<?php

define('FRONT_API_KEY', 'xxxxxxxxxxxxxxxxxxxxxxxxxxx');

/**
 * Performs an API call using cURL
 * 
 * @since 1.0.0
 * 
 * @global string FRONT_API_KEY
 *
 * @param string $url URL.
 * @param string $requestType 'GET', 'PUT', 'PATCH', etc.
 * @param array $postFields Array of fields and values to be posted to URL
 * 
 * @return array Associated array of JSON objects returned from API call.
 * 
 */
function api_call($url, $requestType, $postFields) {

    try {
        $ch = curl_init();
        if ($ch === false) {
            throw new Exception("Failed to initialize");
        }

        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $requestType);
        if (isset($postFields)) {
            $json = json_encode($postFields);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
        }
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_USERAGENT, "curl/7.77.0");
        curl_setopt($ch, CURLINFO_HEADER_OUT, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'Accept: application/json',
            'Content-Type: application/json',
            'Authorization: Bearer ' . FRONT_API_KEY
        ]);

        $content = curl_exec($ch);

        if ($content === false) {
            throw new Exception(curl_error($ch), curl_errno($ch));
        } else {
            $httpReturnCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

            if (($requestType == "GET" && $httpReturnCode != 200) || ($requestType == "PUT" && $httpReturnCode != 204)) {
                throw new Exception("Failed https response. Content: " . $content, $httpReturnCode);
            }
            return json_decode($content, true);
        }
    } catch(Exception $e) {
        // Handle exception
        echo sprintf('Curl failed with error #%d: %s', $e->getCode(), $e->getMessage());

    } finally {
        // Cleanup
        if (is_resource($ch)) {
            curl_close($ch);
        }
    }
}

// Usage - Update Conversation custom fields

$payload = file_get_contents('php://input');
$arrPayload = json_decode($payload, true);
$conversationId = $arrPayload['conversation']['id'];

    $postFields = array(
        "custom_fields" => array(
            "Custom Field 1" => "Some value",
            "Custom Field 2" => "Some value"
        ));

api_call('https://api2.frontapp.com/conversations/'. $conversationId, 'PATCH', $postFields);

?>