CORS policy issue. How to configer the Openhab server

I want to start wrting my own html application what interacts with OH. Calls like

fetch('http://192.168.100.50:8080/rest/items/COPWarmtepomp/state')

work fine. In my VSC I want to use a live server to test my html code. I configured the proxy of the live server as below.

  "liveServer.settings.proxy": {
    "enable": true,
    "proxyUri": "http://192.168.100.50:8080",
    "baseUri": "/rest"
  },
  "liveServer.settings.root": "/html"
}

This seems to work but. When I check the browser console I get errors

Access to fetch at 'http://192.168.100.50:8080/rest/items/COPWarmtepomp/state' from origin 'http://127.0.0.1:5501' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Who knows hoe to solve this.