无法将Webhook订阅添加到Azure事件网格

我无法在Azure事件网格中添加新的WebHook订阅。有人可以帮忙吗？添加webhook端点时出现以下错误。

{
  "status": "Failed",
  "error": {
    "code": "ResourceDeploymentFailure",
    "message": "The resource operation completed with terminal provisioning state 'Failed'.",
    "details": [
      {
        "code": "Url validation",
        "message": "The attempt to validate the provided endpoint https://webapplication120180427035159.azurewebsites.net/api/values?id=AMif5RXS+Bs0bgsbHnNP8RUcn8ZacH8ETUzHXZ5YlNM= failed. For more details, visit https://aka.ms/esvalidation."
      }
    ]
  }