Where can I find Cannondale bike's serial number if the sticker is missing?

I was looking at a used aluminum frame Cannondale from 2017 but the serial number sticker is missing:

Cannondale bikes will display the serial number on the underside of the frame. It’ll be next to a bar code.

Source: Cannondale registration pgae

I was wondering if the serial number can be found somewhere else on the frame in case of a missing sticker. I have seen it stamped below the bottom bracket in other brands’ aluminum frames, but not on this bike.

Thanks for your help!