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!
I heard back from Cannondale support. The sticker is the only way to know the serial number on their newer bikes:

No, the serial number is not stamped on the frame. It is underneath the bottom bracket on a sticker with a bar code, 2 letters + 5 numbers.