Root login alert

Hello.

I think the settings in this document will be helpful.
This requires CloudTrail settings.
https://repost.aws/knowledge-center/root-user-account-eventbridge-rule

You have the answer in the documentation, here: https://docs.aws.amazon.com/prescriptive-guidance/latest/patterns/monitor-iam-root-user-activity.html and this blog post: https://aws.amazon.com/blogs/mt/monitor-and-notify-on-aws-account-root-user-activity/