So the setup code cannot be sniffed, the 8-digit code is a shared secret that's never transmitted, so no diagnostic tool can pull it off the network — that's the whole point of the security. So "read it from the Homebase" is a dead end.
Does the app show you a QR code ? Not the typical pairing one but like one of those square ones ?
If it does, I might be able to help you out …
Or do you have the square QR on the device (without numbers) ?