Can not change Timebase Source on Nucleo-H755ZI-Q dual-core when using FreeRTOS

Hello, I start using Free RTOS on H755ZI dual core, I only use RTOS on core M7, core M4 do nothing and I received a notice from CubeMX:
"CubeMX strongly suggests to use a time-base source other than SysTick when FreeRTOS is used."
But I can not change Systick to other timer be like the image above. What setting step did I miss?

