Credential：id 属性
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2019年9月.
Credential 接口的只读属性 id 返回一个包含凭据标识符的字符串。这可能是 GUID、用户名、电子邮件地址或其他值，具体取决于凭证的类型。