The serial number of the lock can be found in the glue app under Settings -> "Manage locks and properties" - "Your lock".
The serial number can also be found in the box that the lock came with and on the back of the glue lock.
The serial number of the hub is available in the app by clicking on settings at the bottom right of the screen and then select "Manage Wi-Fi hubs". Click on the hub and you will find both the serial number and firmware version is listed on the top.
The serial number can also be found on the box the lock came in and behind the hub's power connector. The plug can be unlocked from the hub by pressing the lock next to it.