How to authenticate via API to allow writes/updates

In the documentation I could find, it seems there were four options.

I explored the API Authentication plugin from miniOrange, and discovered that you can do a lot of things with the free version.

You can GET pages, posts, comments, and media.

You can POST media, comments, and posts.

The plugin supports Basic Authentication, JWT authentication, or (with the premium version,) OAuth 2.0.

So the short answer to my question is, “yes, you can configure authentication for the WP API on your site without incurring big expense.