What can I use to harden acrylic paints or resin?

Asking because while I see that paint hardeners exist in the USA, there doesn't seem to be anything similar in my country (Brazil)

What could I use as a substitute to harden paints? Are there any catalysts or powders that would work?

Google and DDG always show sites/articles about epoxy resins whenever I search for "acrylic hardener", is it safe to assume that catalysts for epoxy, like polyamide, will work with acrylics?