Deployment error {“Code”:2,”RawMessage”:”Failed to create the application reverse proxy”}

[derickcjohn]

I ran into the same issue when I redeployed the app after making a few changes in my Github repo. I changed the app URL, and it worked fine.
Another user waited for 30 minutes, and it was resolved, you can find the post here:

Deployment error {"Code":2,"RawMessage":"Failed to create the application reverse proxy"}

It seems to resolve itself after ~30 min or so, so I will “close” but leave for ref. HTH.