The Sims 3 Late Night Expansion Pack

@Maree033  I've moved your post to the Sims 3 Mac section.

First, run the Origin reset tool for macOS, then see if you can redownload Late Night.

https://help.ea.com/en-us/help/origin/origin/how-to-reset-origin-on-mac/

If LN still shows as installed, it might be, as in, you might not have deleted the actual program files.  If all you deleted was the alias (icon) in the folder in your second screenshot, you can just create a new one.  Here's how:

https://bluebellflora.com/sims-3-packs-not-showing-as-installed/

If the original LN icon from which you're supposed to make an alias in the above instructions isn't there anymore, then yes, you'll need to redownload it.  First though, get rid of any traces of LN on your computer.  Here's how:

https://bluebellflora.com/manually-uninstalling-an-expansion-or-stuff-pack-in-the-sims-3-for-mac/

@puzzlezaddict thank you so much xx