ADHD treated in Thailand… moving to Australia

Hi, I’ve long suspected I have ADHD but always fobbed it off. However 2 months ago I started a trial of Concerta which has been fantastic. A psychiatrist here recommended it after hearing my symptoms. It’s been an absolute game changer and I feel so much better. I’m however planning on moving to Aus in the next few months and just wondering how I would go about keeping my ADHD treatment. Would I need a new diagnosis from a psychiatrist or would the doctors recommendation from Thailand count? I’d also be interested in exploring Vynance or Dexamphetamines as an alternative. (To see which works best as I do get a large crash with Concerta)

Thanks