Background
This is a note on how to search including private posts with the WordPress REST API.
The following was helpful.
https://wordpress.org/support/topic/wordpress-rest-api-posts-not-showing-other-than-published/
Specifically, by using the status argument and specifying multiple statuses as shown below, I was able to retrieve a list of articles including those statuses.
GET /wp-json/wp/v2/posts?status=publish,draft,trash
I hope this serves as a useful reference.