HELP How do i mix two mods together?

[Sneaky Axolxtl]

I'm making a player mod. I'm using the template mod made by Dragon Wolf Leo. I want to make craftables for my character so i downloaded another template for a hat, weapon, and armor made by <default>. I want them to be in the same mod, but how do I do that? I tried putting the custom_item_templates file into my character mod folder, but it doesn't show up in my game. I don't know what to do! How do I mix them together?

[BlueBeka]

Did you merge the "modmain.lua" files? Specifically the "PrefabFiles" list.