Error connecting to Quickbooks Desktop POS through the web connector - quickbooks

Question

I have a client that needs to connect his website to the Quickbooks Desktop POS 18.0. I Downloaded the Quickbooks webconnector, but the latest version gives an error and says I need quickbooks 2015 or later, so I downloaded the 2.1.0.30 version and was able to install it on the machine.
I then used the following php application https://github.com/consolibyte/quickbooks-php. I installed it on my server, got the ssl certificate and everything needed for security. I'm only using it for tests now, but the problem is that when I generate the .qwc file and use it on the web connector I get the following error: Error QBWC1048: QuickBooks Web Connector Could not verify the web application server certificate.
The domain I use is https://filcp.com/
Here is the certificate for the server
This is how my qwc file looks like
<?xml version="1.0"?>
<QBWCXML>
<AppName>My QuickBooks SOAP Server</AppName>
<AppID></AppID>
<AppURL>https://filcp.com/QuickBooks/SOAP/Server.php</AppURL>
<AppDescription>An example QuickBooks SOAP Server</AppDescription>
<AppSupport>https://filcp.com</AppSupport>
<UserName>userName</UserName>
<OwnerID>{57F3JK78-86F1-4FCC-B1FF-9H64VB813D20}</OwnerID>
<FileID>{57F3JK78-86F1-4FCC-B1FF-9H64VB813D20}</FileID>
<QBType>QBPOS</QBType>
<Notify>false</Notify>
<Scheduler>
<RunEveryNMinutes>10</RunEveryNMinutes>
</Scheduler>
<IsReadOnly>false</IsReadOnly>
</QBWCXML>
I followed many tutorials about configuring ie and all, but nothing has worked so far. I can access the application through ie, but I still get that error on the web connector.
Can someone help me to figure out what may be causing it and if there is any other way that I can connect the client's website to Quickbooks POS?

Answer 1

If you visit the URL you're referencing in the .QWC file:
https://filcp.com/QuickBooks/SOAP/Server.php
You can clearly see that you're getting back a response of:
500 Internal Server Error
Your code is broken. Fix your code. If you need further hope, post your code so we can help you. Also, post your logs from the Web Connector (hit the View Log button).