KUBEJS MODDED ARMOR ATTRIBUTES

Ok So, ive been trying for hours to try and give a custom speed effect to "create_more_additions:electrum_armor_chestplate" and the rest of the armor pieces, but nothing will work. I wanted to try and make it go up to 80%, but I'm just lost, messing around with potion effects and other garbage.

Any advice to help an amateur modder such as little old me?