WP REST API v2. filters doesn't work

I'm using WP REST API v2 to get posts.

When I tried to open localhost/wp-json/wp/v2/posts in my browser I got json with all my posts.

I tried to open localhost/wp-json/wp/v2/posts/?category_name=uncategorized and I got the same json though all my posts assigned to specific categories.

Maybe I'm using wrong filter but I tried to open localhost/wp-json/wp/v2/media?post_parent=15 from first json and got all media on my site instead of one attached to the post

What I'm doing wrong with this?

via Chebli Mohamed