google 账户突然要电话号码短信验证，我该怎么办？

新注册的 google 帐号没几个月，备用邮箱，2fa 都写了，电话没绑定。

今天登录时突然就让验证电话号码了

Verify it's you

There is something unusual about your activity. For your security, Google wants to make sure it's really you.

Enter a phone number to get a text message with a verification code.

Google will store this number and only use it for security purposes. Standard message and data rates may apply.

长期在国内使用的帐号，是不是应该买个美国实体电话卡来绑定？其他国家的电话卡可以吗？有没有性价比高的推荐？