payment wall pingback url issue.

[0xffset]

Hi, 
I am trying to setup paymentwall with their plugin provided here: https://www.paymentwall.com/en/documentation/IP-Board/1760

I setup everything according to their website, everything seems to work fine, the widget shows up on the website along with the test product etc. But when trying to submit the website for "review" I keep failing the "Test pingback" check.

Here is the error I get:

Pingback wasn't successful. Reason: Response body does not match the expected pattern: OK

Request:

GET /index.php?app=nexus&module=checkout&controller=pwPingback&uid=&goodsid=&slength=&speriod=&type=0&ref=&is_test=1&sign_version=2&sig=194a1aca2d3faac3351b2a64e377e8d9 HTTP/1.1
Host: xxxxxx.com
Connection: close
Accept-encoding: gzip, deflate
User-Agent: Paymentwall API

Response:

HTTP/1.1 200 OK
Date: Fri, 02 Jun 2017 04:02:11 GMT
Content-type: text/html; charset=UTF-8
Transfer-encoding: chunked
Connection: close
Set-cookie: __cfduid=d489b788d97872b7e3c7aefadab1f2b7d1496376131; expires=Sat, 02-Jun-18 04:02:11 GMT; path=/; domain=.xxxxxxx.com; HttpOnly
Set-cookie: ips4_IPSSessionFront=jbomo4kt4bc7198reeo0inhk17; path=/; secure; HttpOnly
Vary: Accept-Encoding
X-powered-by: PHP/7.0.18
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-control: no-store, no-cache, must-revalidate
Pragma: no-cache
Server: cloudflare-nginx
Cf-ray: 36878403faac591b-DFW
Content-encoding: gzip

Transaction invalid!

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