I found a Model of this Case for Thermometer and Hygrometer, but the STL i found somewhere was not working due to missng airflow.
I have changed the case so that the necessary airflow is given.
in addition you need the standard 44 mm thermoeter like this one
Goxawee 50~70°c/ 58~158°f Mini Eingebettetes Thermometer - Temu Germany
the Goxawee need a 103% print some others are better with 101% scaled print
and lastr but not least batteries called LR44
Enjoy and to whom who has created the initial STL, hope you are fine with this moduification