Hi Crane,
If you are trying to avoid any/all use of dynamic memory allocation, then you will need to supply an implementation of vApplicationGetTimerTaskMemory(). That function helps FreeRTOS know where you have provided memory for the timer task. By convention, anything in FreeRTOS that starts with “Application” is meant to be provided by the application (not by FreeRTOS).
However, if you are OK with some use of dynamic memory allocation, then you can add this to your FreeRTOSConfig.h:
#define configSUPPORT_DYNAMIC_ALLOCATION 1
In that case, you don’t need to provide an implementation of vApplicationGetTimerTaskMemory().