It is nonsensical to claim that anything other than my brain could produce the same consciousness that my brain is producing. It's obviously far beyond anything any conceivable digital computer could ever reasonably simulate, and even if you did create a "good" simulation it obviously wouldn't have the same properties that my brain does because it's an entirely different thing than my brain is.
In any case, a closely-but-not-perfectly-accurate simulation of a real human brain is still going to be human, unless you believe that someone becomes less human when they're experiencing some kind of cognitive decline, or a stroke, or other biological malfunctions. The point is, there is nothing essential to the having of a physical brain that creates the concept of consciousness or sense-of-self.
And there absolutely is something essential to the concept of being human that we are entirely incapable of replicating artificially. In fact as far as I know we are incapable of synthesizing any kind of life whatsoever. We can't even create the simplest type of living cell imaginable.
So to claim that we could just create consciousness, a fundamental property of this "life" thing that we don't properly understand, within a piece of rock is beyond naive. We don't even know what it is or how it is.
We understand quite well where in the brain the sensation of self-awareness / self-experience / sense-of-self comes from. We have evidence that disruption of that part of the brain breaks those sensations.
Okay now tell me where in the LLM its alleged consciousness comes from.