I'm continuing treatment from another country and don't want to start completely over — what service actually fits that situation?

Moved to Canada a few months ago, was already diagnosed and treated for ADHD back home for years. Every service tier I look at seems built around either a completely new patient or someone with zero prior history, and I don't quite fit either box cleanly, don't want to redo everything from scratch but also understand a foreign diagnosis probably isn't automatically valid here.