In the AWS Management Console search bar, type EC2.
In the left Navigation pane click on Instances under the Instances section.
Select your EC2 Instance and in the Instance Details pane below, select Storage to view the Block Devices and then click on the Volume ID of your additional EBS Volume attached previously (e.g. /dev/sdh; the device name may be different in your case).
This will open the Volumes page showing the specific Volume details.