> Next, we need to log in with our Ubiquiti account.
Right. They don't learn.
> You can also proceed without an Ubiquiti account
Can you? Or you have to make one and only then maybe possibly to some extent run the thing without one?
Nothing in the Ubiquiti ecosystem requires you to use the cloud. Even fully air-gapped setups are supported.
You really don't need a Ubiquiti account. They of course make it the default, but you can check a "local user only" box and then just create a local user with a username and password. I really appreciate this about them. You don't need internet to set it up.