Is there a way to legitimately register the shiny Eternamax on the SwSh dex?

[Samekh]

Now that shiny Eternatus is out, is there a way to legitimately register the shiny Eternamax on the SwSh dex or is that only possible by editing your save using PKHeX?

I tried using Eternabeam, but that also doesn't work.

Edited September 18, 2022 by Samekh

[theSLAYER]

If owning one legitimately doesn't do it, then there isn't a way.

You could try transferring a Shiny Eternatus to a baby save and bringing it through the Eternatus story arc, and see if that works.