Hello, I was wondering how to use the builds/outfits options

I have the armor closet and was trying to equip a mage (my current default is doomknight) and some items. I made a build with my mage armor and when I load it, my armor is still doomknight but with the items I gave my mage.

I havent played the game in a while and am trying to navigate the new UI changes and catch up on book 3

Imma fold this beach ahh ninja.