when opening dialog keeps getting error No handler found on any channel for message:

[wernerholzapfel]

I keep getting this error:
SDK.min.js:1 No handler found on any channel for message:

Documentation seems to be outdated ->
Not working: IHostDialogService doesn't exist.
https://github.com/MicrosoftDocs/azure-devops-docs/blob/main/docs/extend/develop/using-host-dialog.md

These are my contributions

{
            "id": "release-work-item-form-page",
            "type": "ms.vss-work-web.work-item-form-page",
            "description": "Release work item form page",
            "targets": [
                "ms.vss-work-web.work-item-form"
            ],
            "properties": {
                "name": "Release",
                "uri": "https://localhost:3000/workitem.html"
            }
        },
        {
            "id": "release-form",
            "type": "ms.vss-web.external-content",
            "description": "The content to be displayed in the dialog",
            "targets": [],
            "properties": {
                "uri": "https://localhost:3000/dialog.html"
            }
        },

In workitem I open the dialog:

async function openFullDialog() {
  const layoutSvc = await SDK.getService<IHostPageLayoutService>(CommonServiceIds.HostPageLayoutService);
  const extensionCtx = SDK.getExtensionContext();
  const contributionId = `${extensionCtx.publisherId}.${extensionCtx.extensionId}.release-form`;

  layoutSvc.openCustomDialog(contributionId, {
    title: "titel",
    onClose: result => {
      console.log("dialoog gesloten:", result)
    }
  });

}

and in dialog:

 useEffect(() => { 
const extensionCtx = SDK.getExtensionContext();
  
    const contributionId = `${extensionCtx.publisherId}.${extensionCtx.extensionId}.release-form`;

    SDK.register(contributionId, {});

    SDK.ready().then(() => {
    })

  }, []);