Web item with dialog target redirecting to 404

{
            "key": "sys-header-left",
            "location": "system.header/left",
            "context": "addon",
            "name":
            {
              "value": "Anne System Header Left"
            },
            "url": "/hello-world?app=jira&accountId={user.accountId}",
            "conditions": [
              {
                "condition": "user_is_logged_in"
              }
            ],
            "tooltip": {
              "value": "Anne Wizard"
            },
            "target": {
              "type": "dialog",
              "options": {
                "width": "840px",
                "height": "373px"
              }
            }
          }