Serial number doesn't appear under device list
I need the serial number of lost/stolen macbook air. I dont have original packaging. I signed into apple id and looked under devices to retrieve it. However, unlike the examples on the apple community website, the serial number is not present under the device list. Only device name, model and version are present.
How can I retrieve serial number without original packaging or with the device itself?
MacBook Air 13", macOS 10.13