You just download the mod and double click it, as it is an application, just like TPT.
dofile("my-lua-mod-file-name-goes-here.lua"), if you've taken the Lua code and placed it next to Powder.exe into a file called my-lua-mod-file-name-goes-here.lua .
Boxmein I dont understand and Im doing the exact same as you but it is not working for the Lua Mods
For a Lua mod, you could use cracker64's script manager, or you could save it as autorun.lua in the same folder as TPT, or you could type in the console 'dofile("name_of_your_script.lua")'.