IUP is not working for Lua and throws an error that the module is not found, even if the file IUP is calling is in the same file

Question

I have installed the IUP GUI for Lua (https://www.tecgraf.puc-rio.br/iup/, the website is in English, although it doesn't look like it). I have tried running IUP on my computer using their tutorial code:

require("iuplua")

iup.Message("Hello World 1","Hello world from IUP.")

-- to be able to run this script inside another context

if (iup.MainLoopLevel()==0) then

iup.MainLoop()

iup.Close()

end

but whenever I do I get this error: module 'iuplua' not found and then I get a bunch of other errors below that :

no field package.preload['iuplua']

no file '.\iuplua.lua'
no file 'C:\Users\user\bin\lua\iuplua.lua'
no file 'C:\Users\user\bin\lua\iuplua\init.lua'
no file './iuplua.lua'
no file './iuplua/init.lua'
no file './lua/iuplua.lua'
no file './lua/iuplua/init.lua'
no file 'C:\Users\user\lualibs/iuplua/iuplua.lua'
no file 'C:\Users\user\lualibs/iuplua.lua'
no file 'C:\Users\user\lualibs/iuplua/iuplua/init.lua'
no file 'C:\Users\user\lualibs/iuplua/init.lua'
no file '.\iuplua.dll'
no file 'C:\Users\user\bin\iuplua.dll'
no file 'C:\Users\user\bin\loadall.dll'
no file 'C:\Users\user\bin/clibs/iuplua.dll

This occurs even if I put the file I'm running into the srclua5 folder which contains a file called "iuplua.lua". Why does this occur? Could someone please help?