Live Streaming App issue - Custom is greyed out

I am trying to stream to a Facebook Group and since the 22nd April, 24 removal of third-party apps to do this I have to use a Zoom to do this. I turned on the ability via the switch on the desktop zoom account to allow integrations and apps. I did try to do a custom setup and it had an error so I removed it - and now the custom section is greyed out - I am beyond trying to work out what zoom setting needs changing. I have turned on and off the switch - reset the app - still nothing - any thoughts... Kind of desperate.