HBO Max was recently made available in Australia. Can you please make it available as an option in the “Watch Now” settings?
We get our streaming services data from JustWatch. The service would need to be added there before it could be added to Trakt. I would suggest reaching out to them to request the service be added: https://support.justwatch.com/hc/en-us/articles/360020823238-Can-you-add-service-to-JustWatch