union-php/vendor/volcengine/volc-sdk-php/examples/Visual/DemoFaceSwap.php

<?php
require('../../vendor/autoload.php');
use Volc\Service\Visual;

$client = Visual::getInstance();
// call below method if you dont set ak and sk in ～/.volc/config

$client->setAccessKey($ak);
$client->setSecretKey($sk);

echo "\nDemo FaceSwap\n";
$response = $client->FaceSwap(['form_params' => [
    'image_base64' => '', 'template_base64' => '', 'action_id' => 'faceswap']]);
echo $response;