At the start of the series, Faragonda explains a fairy earns her Enchantix when saving someone from their planet.
This leaves many arguing Tecna's Enchantix is a plot hole, as her sacrifice saves Andros, which isn't her home world nor had her people on it.
But I argue it makes sense, as with her sacrifice Tecna did save someone from Zenith: herself.
Hadn't she closed the portal, everyone on Andros would have died, her included.
It was only her sacrifice that saved her (& everyone else), earning her Enchantix.