may help on picking out a good conditioner.
What you are looking for in a conditioner is one that removes chlorine/chloramine, and binds heavy metals.
Seachem Prime, API Stress Coat, Hagen/Nutrafin Aquaplus and AquaScience Ultimate are good ones that do all of that, and some have extra benefits.
You don't have to have one that says for bettas specific- some of those just do that in hopes to sell more since bettas are pretty popular because they are marketed as "easy" fish that require minimal care.
Unsure what is available where you are, but there are some resident Australians here in the forums and hopefully one will pop in and tell you what is available.