Approval for Vyvanse as an Australian

Hi!

Going over in February next year for two weeks, but I'm curious as to who I need to contact to apply to take my Vyvanse with me.
Do I have my GP sign, or try to contact my psychiatrist? My GP has authority over my Vyvanse, but then I'm paranoid about whether this won't be accepted and I'll need my "original prescriber" to sign for me.
I have no clue when I'll be able to see my psychiatrist next, and it's much easier to see my GP.

Does anyone have any advice? ☺️ Thank you so much!

by ribumbee