marking articles as read always returns null

[DrRibosome]

Marking articles as read always returns null.

I followed the docs here, but have been unable to mark an article as read with either the DELETE or POST methods. Instead, I always see a 200 response status, with a body of simply null. Then, when I query for unread articles, the article continues to show up (the docs do mention that if it doesnt return a list of responses then it didnt go through).

my submitted response body looks like:

{"unread_entries":[1993562351]}

Is there something im missing?

[DrRibosome]

after playing around, found that I did not set the content type to application/json as required