Cup holder for carry-on luggage

My daughter likes to use her carry-on luggage as schoolbag, so I made this cup holder.

Note:

This cup holder is for:
Parker Small Carry-On Rolling Luggage
https://www.kipling-usa.com/parker-small-carry-on-rolling-luggage/WL4799.html
https://www.thermos.com/kids.html

For other sizes, please use my customizable design: https://www.thingiverse.com/thing:2812261