Pfthb

This question has been asked a gazillion times. I've read the mozilla documentation and looked through so many answers my eyes hurt.

In my ajax call I have this:

 $.ajax({
 type: 'POST',
 dataType: 'json',
 data: name: "test",
 contentType: 'application/json',
 url: 'https://example.com:8443',
 success: function (data) 
 alert(data);
 

in my express server my server.js file is this:

app.post('/', function (req, res) 
 console.log(req.body.myData);
 res.header('Access-Control-Allow-Origin: *');
 res.header('Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS');
 res.header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token');
 return res.end('<h1>Hello, Secure World!</h1>');
);

from my understanding I'm properly making the ajax call with dataType: 'json', and contentType 'application/json'.

Also I'm setting acess control allow origin to * which should allow me to have any domain hit my server. I can't figure out what I'm doing wrong. I get this error:

has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Any help would be appreciated!

My error was a dumb one. In express js this is incorrect:

res.header('Access-Control-Allow-Origin: *');
 res.header('Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS');
 res.header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token');

The settings should actually be like this '','' not ':'

The correct syntax that worked is this:
 res.header('Access-Control-Allow-Origin', '*');
 res.header('Access-Control-Allow-Methods', 'GET, POST, PUT');
 res.header('Access-Control-Allow-Headers', 'X-Requested-With, Content-Type');

EDIT: Using * is a security risk but in this case it's one server testing on another both of which I own. When going live I would set * to example.com