You can find the downloads for this mod on its page.
https://www.neonoceancreations.com/mods/s4/refer
Note: You can get to The Sims 4 mod folder by going to your documents folder, then to Electronic Arts > The Sims 4 > Mods (You must have run the game at least once for the mod folder to appear).
If you would like to install this mod automatically, download this mod's installer. The installer is an executable that can automatically add this mod to your game but currently only works for Windows computers. With the installer, old versions that where correctly installed will be automatically removed. You will also be prompted to enable the game's mod support settings if they aren't already.
If you would like to install this mod manually, download the mod's files prepackaged in a zip folder. After you've downloaded this go through the following instructions to manually install this mod.