Use ellomenop's version of the mod found here:
https://github.com/ellomenop/Hades2-LootChoiceExtension/tree/main
https://thunderstore.io/c/hades-ii/p/ellomenop/LootChoiceExtension/
A Hades 2 Mod created to extend the amount of boon choices from the default 3.
Originally created by Magic_Gonads for Hades 1, this is the Hades 2 version of the same mod.
-- Made with help from ellomenop from the Hades Modding Discord.
https://discord.gg/6nfzbnMYce