Arduino for STM32

ok, so my next question will be, how do I put the M0 core to sleep as well? Does the lowpower module support this somehow too?

Trying to get my Nucleo--WL55JC1 board into some super low power sleep.
Currently my code is quite minimal:

#include <Arduino.h>
#include <RadioLib.h>
#include "STM32LowPower.h"

STM32WLx radio = new STM32WLx_Module();
void setup()
{
LowPower.begin();
radio.sleep(); // didnt really help
}

void ...