It means a server has rejected a request because the message content format is not supported.

I read that this is referring to the headers Content-Type. But what I have there is right from Spotifys documentation.

I changed the body type to JSON and now its giving me this error:

Status code 400
{“error”:“unsupported_grant_type”,“error_description”:“grant_type parameter is missing”}

But Spotifys documentation says this to enter “authorization_code” which is what I have.