All POST requests require a set of headers to be sent on every request in order for the API to function correctly. I've created example POST requests in each endpoints documentation on how exactly you would apply these headers to a request.

Header Type Usage
Accept application/json Required
Content-Type application/x-www-form-urlencoded Required
Authorization Bearer {ACCESS-TOKEN} Required

{primary} The Authorization header {ACCESS-TOKEN} must be replaced with an actual Access Token