Re: Custom content not showing up in game?

via in-game settings, make sure you have 'Enable Custom Content and Mods' checked ✓ . (You should see it under the Other tab in the in-game settings) Quit the game after selecting Apply Changes and then launch the game again for these changes to work.

This guide should be up to date: https://www.carls-sims-4-guide.com/tutorials/mods-cc.php