Error link external C library

Good morning,

I would like to ask for support in solving a problem that arises when updating a simulink model in which I would like to import external libraries written in C code for STM32 microcontrollers.

After having done all the includes, I can insert the functions in the library using C Caller (I see all the functions), but during the compilation phase I get an error that I report in the attached figure.

Thank you