Sounds like they need to work on their UX then because if people here aren't getting it working then it seems likely that most of their users aren't able to. Is it a default installed plugin in Safari?
And the answer is, it's not installed by default, but there are a variety of third-party plugins available in the App Store.
There is a firehouse of options in the app store, but you need to sift through conflicting reports about which ones are "still good" - the prevailing recommendations seemed to change every 6 months or so when I researched which ones to try.
When you do find some that seem worthwhile, the paid tiers are often expensive, and they will not work as well as the free browser extensions on every other platform.
And there is no replacement for NoScript at any price.