PHP POST Request returning 404 status code

Question

I am making a post request which returns 200 status code on success and works fine when I try it using postman.

When I try to make a POST request using PHP, it succeeds but with a 404 status code.

Here is my code.

            $url = 'my_url';
            $data = array('key1' => 'value1', 'key2' => 
            'value2');
            $options = array(
                'http' => array(
                    'method'  => 'POST',
                    'content' => json_encode( $data ),
                    'header'=>  "Content-Type: application/json\r\n",
                    'ignore_errors' => true
                )
            );
            $context  = stream_context_create( $options );
            $result = file_get_contents( $url, false, $context );
            $response = json_decode( $result );
            $headers = get_headers($url);
            Helper::pre_die($headers);
            $code = substr($headers[0], 9, 3);

Here is the header I get:

    Array
    (
        [0] => HTTP/1.1 404 Not Found
        [1] => Server: nginx/1.14.0 (Ubuntu)
        [2] => Date: Sun, 01 Sep 2019 07:52:34 GMT
        [3] => Content-Type: text/html; charset=utf-8
        [4] => Content-Length: 146
        [5] => Connection: close
        [6] => X-Powered-By: Express
        [7] => Vary: Origin, Accept-Encoding
        [8] => Content-Security-Policy: default-src 'self'
        [9] => X-Content-Type-Options: nosniff
    )

Any help will be greatly appreciated.