This means, "Look up the value of the toggle in Gallery1 where the var column matches the name of your "variable". Alternatively, you could lookup the value in the collection, but you get the same result.
It may be easier to place the toggles individually in a container like a canvas:
I'll look through the resources you provide and see if I can make it work. Still unsure whether I can store a variable in a Gallery then toggle it using the Lookup function. Can't wait to play with that one.
RE: Importing the app: Its not really an import, but rather an extract and open.
Open PowerApps web studio
Under "Open" there is a "Browse" option to browse your local filesystem