Installing Guardduty Agent on EC2 Ubuntu Linux Instance

GuardDuty agent is designed to be installed on Amazon Linux 2 instances, and there isn't official support for installing it on Ubuntu or other Linux distributions. However, you may still be able to manually install and configure the agent on your Ubuntu instance, but it may not be officially supported or fully compatible.

Keep in mind that while it may be possible to install the GuardDuty agent on Ubuntu, it's not officially supported, and you may encounter limitations or issues. Consider using an Amazon Linux 2 instance if GuardDuty integration is a critical requirement for your workload.

I guess you can getting the error from Systems Manager while running AmazonGuardDuty-ConfigureRuntimeMonitoringSsmPlugin document.

As per Installing the security agent manually method 2, only RPM packages are available. There are currently no .DEB packages for installation on Ubuntu.