Generating the correct codes and secret that work...

Hi everyone.  I have recently restarted a extension of a membership system to automatically add contacts and raise some invoices in MYOB Business.  I am the developer, but that is not my problem.

My issue is that I am unable to generate the right codes that work from the developer platform.  It complains about each attempt.  I have successfully written such oAuth2 interfaces previously.  I am assuming it thinks I want to use a different interface.  The codes i generate - simply do not work.

I think this is related to my original registration a few years ago.  I thought I would be writing a Windows desktop program.  However, now, I am using a web based backend using PHP, HTML and JS.  I think that is the problem I am having – but am not sure.  I cannot find anyone to talk to.

I have gone through three tickets asking this question – I think one is still open – that was weeks ago.  I keep having tickets closed without any interaction telling me to have the developer raise the ticket.

Hence, I am a little frustrated.  How should I proceed?  Any guidance on getting my situation corrected would be appreciated.