There are a couple of products available in DriveThruRPG that deal with the Bronze Age, but you'll need to convert them to HERO:
Into the Bronze (OSR): https://preview.drivethrurpg.com/en/product/318919/Into-the-Bronze--OSR-Bronze-Age-Sword-and-Sorcery
Mythic Babylon (Runequest): https://preview.drivethrurpg.com/en/product/355333/Mythic-Babylon
Glorantha, Runequest's default setting, is also has a late Bronze Age or early Iron Age level of culture and technology.