I'm having trouble understanding the WordPress.com REST API documentation. The example given for GET /sites/$site/posts/ is

curl 'https://public-api.wordpress.com/rest/v1.1/sites/en.blog.wordpre
+ss.com/posts/?number=2'
[download]

which I couldn't figure out how to make work.

By contrast, the example provided in A Beginners’s Guide to the WordPress REST API is

curl -X GET -i http://the-art-of-autism.com/wp-json/wp/v2/posts
[download]

which does work.

Can you help me reconcile the two (which will hopefully help me interpret the rest of the WordPress REST API documentation)?

Also, do REST API Resources only work on premium WordPress sites? I was able to execute GET /sites/$site/posts/ on the-art-of-autism.com (a premium site) but not on anautismobserver.wordpress.com (a free site). Do you know the reason for this?

I really appreciate your help. You've already saved me a great deal of time and effort (and greatly increased my success chances). Thank you ever so much.