WooCommerce: Call the Thankyou from my php file - woocommerce

Question

I am new to WooCommerce. After the payment is made I am redirected to another PHP file (testpayresult.php). From this file, I need redirect to the Thankyou page in WooCommerce. How do I achieve this?
Sending the order details to the payment gateway API:
echo '<script src="https://test.oppwa.com/v1/paymentWidgets.js?checkoutId='. $responseData->id . '"></script>';
echo '<form action="/wp-content/plugins/woo-payment-gateway-for-taurus-datafast/testpayresult.php" class="paymentWidgets" data-brands="VISA MASTER AMEX DINER DISCOVER"> </form>';
echo '<form action="/wp-content/plugins/woo-payment-gateway-for-taurus-datafast/testpayresult.php" class="paymentWidgets" data-brands="VISA MASTER AMEX DINER DISCOVER"> </form>';
The testpayresult.php file:
<?php
echo "Payment Over";
echo "<br />POST<br />";
$resourcePath = '/v1/checkout/' . $_GET["id"] . "/payment"; //$_GET["resourcePath"];
echo "<br /> Resource Path: " . $resourcePath;
$entityId = $_GET["id"];
echo "<br /> Entity Id: " . $entityId;
//echo "<br /><br /> Thanks Page URL: " . get_option( 'woocommerce_thanks_page_id' );
echo "<br />";
function check_transaction_status($presourcePath, $pentityId)
{
$url = "https://test.oppwa.com" . $presourcePath;
$url .= "?entityId=8ac7a4ca7402389d0174023e6b6b001c";
echo "<br />URL: " . $url;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Authorization:Bearer OGE4Mjk0MTg1YTY1YmY1ZTAxNWE2YzhjNzI4YzBkOTV8YmZxR3F3UTMyWA=='
));
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // this should be set to true in production
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$responseData = curl_exec($ch);
if (curl_errno($ch)) {
return curl_error($ch);
}
curl_close($ch);
return $responseData;
}
$response = check_transaction_status($resourcePath, $entityId);

Answer 1

How do I get the order Id in the testpayresultfile.php?
It is called by the submit in the generate_taurusdatafast_form($order) function in the wooshop-taurus-datafast.php file
Code in Github