The Sims 4 Deluxe Party upgrade (PS4)

I bought the Deluxe Party Edition upgrade for The Sims 4 on PS4.

If I go to the PS store to download it, it shows a download button but when I press it, it refreshes the screen and it doesn't start downloading.

When I try to download it from a browser it doesn't show the download button, instead it just says purchased.

How can I access this content?

In Sims 4, the content is already in the game, by buying the upgrades/expacs/etc you essentially "unlock" the content.

I'd advise you to first check the Notifications section to see if anything was actually downloaded and then simply boot up the game and see if the content advertised by this upgrade is actually available to plop down.