In The Amazing Digital Circus , there isn’t any confirmed canon explanation that Jax “got his brain scanned” yet. That idea comes from fan theories and discussion, not an established on-screen fact.

What the theory says

The brain-scan idea usually claims the headset or device scanned the players’ minds and made digital versions of them. In that version of the story, Jax would have entered the circus the same way as the others, but the “scan” part is still speculation.

What is actually known

Jax is a main character in the series, but the available sources here do not show an official explanation for how he was created or transported into the Digital Circus. A lot of recent posts and videos discuss twists, leaks, and theories, but those are interpretations rather than confirmed lore.

Simple answer

So the safest answer is: we don’t know for sure yet. The “brain scan” explanation is a popular fan theory, not confirmed canon.

TL;DR: Jax’s brain-scan origin is a theory, not an official reveal.