Terminalia catappa is a fruit tree. People brew its dried leaves into tea. The seed kernel is edible raw or cooked. This plant is not the same as Haritaki (Terminalia chebula).
Someone might reach for it when they want a gentle antioxidant or to help maintain skin health. Direct research on humans is thin. Most use comes from long standing tradition.
Dried leaf infusions and eating the kernel are the typical routes.