I made the mistake of cleaning with boiling water the original button so I modeled this one as a replacement.

You can find the original thermos here (or in may other places, it's often rebranded): https://www.amazon.it/dp/B09SZL233P/

Remember to print with you strongest settings and with food safe filament (PLA or PETG).

With my prusa mini i used 0.15 layer height, no supports, 100% infill.

You'll probably need to sand it and clean off the model after printing.

Fit is pretty thigh, when mounting be very careful.