I have a flow that was working in 11.1. It sends an email when an incident is created in Field Maps. We have upgraded to 11.3 and our connection to the Enterprise is broken. I tried re-registering my custom application in the portal but it wouldn't accept the new client ID. ESRI tech support told me to replace the client ID with 'arcgisforpowerautomate' and this doesn't work either. I either get this error:

Or this one:

I get this error whether I add the client ID or 'arcgisforpowerautomate'