Sending a POST request to the authorization endpoint results in 304

When running

curl -X POST "http://192.168.0.39:16021/api/v1/new" -D -

on my Macbook connected to the same wifi as my Nanoleaf, it responds with

HTTP/1.1 403 Forbidden
Content-Length: 0

Any ideas why?
Thanks!

Hold down the power button on the controller for 5 seconds until the controller LEDs start flashing and then resend the request within 30 seconds.

Hope this helps

Already doing that. My bad. Thanks though

Do you see the LEDs flash after holding down the power button for 5 seconds?