What happened to the Post Processing Stack from Unity Technologies? Is there an alternative?

I’m following this tutorial from around 2017, and now I’m on the part about using the Post Processing Stack from Unity. It’s no longer there. What happened to it?

The original version of the post-processing stack was hosted on the asset store, but was deprecated a year or so ago. Instead, you’ll have to use the new volume-based version which you can find in the package manager;

https://docs.unity3d.com/Packages/com.unity.postprocessing@2.3/manual/index.html

Just go to the package manager and you can install the post processing package!