Sounds like your problem is moreso that you struggle to load a lunalua library regardless of the editor or anything.
By default, the file names luna.lua will run for your level. You can create it in the editor if you go into script -> lunalua local. This will create a file and open it.
To then load a library, put:
local myLibrary = require("libraryname")
so for this case:
local anotherWalljump = require("anotherwalljump")
This assumes anotherwalljump is in the level folder.
For anotherwalljump, the topic I posted also contains an usage example directly below the gif spoiler:
viewtopic.php?f=101&t=24793