Custom Upgrades

[FkAzzerothG]

Hey there, I need some help I've tried to make so that the zerg hive can morph into a Leviathan and I made a custom version of UpgradeToLair (Hatchery - Morph Building (Hatchery -> Lair)) and changed some stuff but then when I look for it I can seem to find it to add it to the Hive.

PS: Please be quite basic since this editor is very very new for me, and I'm used to the WC3 editor.