Does XIAO Nrf52840 support RTOS?

I’m learning the RTOS example. I download Seeed_Arduino_FreeRTOS repositories and following the tutorial. However none of the examples can be verified. One of the errors said:
src\FreeRTOSVariant.c:192:2: error: #error “Processor or architecture not support!”
I notice nRF52840 has ARM® Cortex®-M4 which is supported by FreeRTOS. Could anyone help me why this error comes out?