Sleep and wakeup doesn't work with ArduinoLowpower.h on XIAO nrf52840 mbed

Hi

The ArduinoLowPower.h gives error at translation time, (and warning as well, that it is not compatilbe with the mbed “WARNING: library Arduino Low Power claims to run on samd, nrf52 architecture(s) and may be incompatible with your current board which runs on mbed architecture(s).” - and it really doesn’t work.

Any guess - How I can do sleep and wake up on that board with mbed?
(adafruit not good here.)

Wake up must be external for a pin state change.

Thanks,

Szabolcs