Status Code: 403 The origin "null" is not authorized?

[x-fran]

What am I missing here?

Request URL: http://some.domain.com.local/gp-test/method-notification
Request Method: POST
Status Code: 403 The origin "null" is not authorized

**General
Request URL: http://some.domain.com.local/gp-test/method-notification
Request Method: POST
Status Code: 403 The origin "null" is not authorized
Remote Address: 127.0.0.1:80
Referrer Policy: strict-origin-when-cross-origin

**Response headers
Access-Control-Allow-Credentials: true
Access-Control-Allow-Methods: GET, PUT, POST, DELETE, HEAD, OPTIONS
Access-Control-Allow-Origin: https://test.portal.gpwebpay.com
Connection: Keep-Alive
Content-Length: 0
Content-Type: text/html; charset=UTF-8
Date: Thu, 20 May 2021 10:42:07 GMT
Keep-Alive: timeout=5, max=97

**Request headers
Server: Apache/2.4.41 (Ubuntu)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9,es;q=0.8,ro;q=0.7
Cache-Control: max-age=0
Connection: keep-alive
Content-Length: 110
Content-Type: application/x-www-form-urlencoded
Host: some.domain.com.local
Origin: null
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36

** Form data
threeDSMethodData: ewogICJ0aHJlZURTU2VydmVyVHJhbnNJRCIgOiAiNGRkODMxYmItYjI1My00Mzk1LThkNmItZGY5YmNlN2VlMzk0Igp9