To detect and alert on activities performed by a root account, an audit event policy should be used. An audit event policy is a type of policy that can be used to detect suspicious activities or events that may be related to security threats. This type of policy will allow the administrator to monitor and alert on any activities performed by a root account.
https://docs.paloaltonetworks.com/prisma/prisma-cloud/prisma-cloud-admin/prisma-cloud-policies/prisma-cloud-threat-detection