confluence-php-xmlrpc-avatar-example.php

<?php

$client = new \Zend\XmlRpc\Client('https://example.com/rpc/xmlrpc'); // INSERT your hostname
$token = $client->call('confluence2.login', ['USERNAME','PASSWORD']); // INSERT your user + pass

try {
    $profilePictureData = file_get_contents('/path/to/your/image/file.jpg'); // INSERT path to the file
    $profilePictureData = new \Zend\XmlRpc\Value\Base64($profilePictureData);
    // REPLACE "confluence-username" with the username of the user to update
    $result = $client->call('confluence2.addProfilePicture', [$token, 'confluence-username', 'file.jpg', 'image/jpg', $profilePictureData]);
} catch (\Exception $e) {
    echo $e->getMessage() . "\n";
}

install.sh

composer require zendframework/zend-xmlrpc