"Share WebGL game" does not exist in package manager even with previews enabled

I'm following this tutorial posted by Unity as I'd like to share my game on the WebGL setup: https://www.youtube.com/watch?v=L82geOfpQCQ&list=PLIHn8wpu1z2EXxCIH8sRtEOnIGqRrbYkg∈dex=5

However, the "share webGL game" package does not exist in the package manager. This has been reported in another thread, where the proposed solution was to use the advanced settings to enable previews: https://answers.unity.com/questions/1722568/share-webgl-game-is-not-found-in-package-manager.html

Similar to the comments on that thread, this solution did not work for me. See the attached screenshots. Also, note that the layout of my version of Unity (2020.1.6f1) seems to have a different UI layout.

Lastly, the package is not in "In Project," "my assets," or "built in."