I was not aware you could this: [WayBack] UniFi – Install a UniFi Cloud Controller on Amazon Web Services – Ubiquiti Networks Support and Help Center
Giving it a bit more thought, I’m not sure I would want this, as it would presume you have an internet connection that is up on the WAN side.
You’d need this before installing any of your Unify equiment, even when installing your first Unify router, which would mean a chicken and egg problem.
Also it would mean you can only use the cloud key when the WAN is down, you cannot use the cloud-key, not even locally.
–jeroen