sample of sleep and wakeup on RTC using seeeduino xiao and Arduino-IDE

xiao_sleepRtc.ino

// sleep and wake test using RTC
// for seeeduino xiao
#include "RTC_SAMD21.h" //install seeed_arduino_RTC : https://github.com/Seeed-Studio/Seeed_Arduino_RTC
#include "DateTime.h"
#include <EnergySaving.h>

EnergySaving myPowSave;
RTC_SAMD21 myRtc;

#define PIN_LED 13

void setup()
{
  myRtc.begin();
  Serial.begin(115200);

  pinMode(PIN_LED,OUTPUT);
  digitalWrite(PIN_LED,HIGH);//LED off (active LOW)

  myRtc.adjust(DateTime(2030, 4, 1, 8, 30, 0) );
  myRtc.attachInterrupt(dummyfunc); 
  myPowSave.begin(WAKE_RTC_ALARM); 

  myRtc.disableAlarm();
  DateTime timeNow = myRtc.now();
  const uint16_t uiAlmNextSec = 10;
  DateTime timeAlarm = DateTime(timeNow.year(), timeNow.month(), timeNow.day(), timeNow.hour(), timeNow.minute(), timeNow.second() + uiAlmNextSec);
  myRtc.setAlarm(timeAlarm);
  myRtc.enableAlarm(myRtc.MATCH_SS); 

}

void loop()
{
  
  for(uint16_t uilp=0; uilp<3; uilp++)
  {
    digitalWrite(PIN_LED,HIGH);
    delay(1000);
    digitalWrite(PIN_LED,LOW);
    delay(1000);
  }
  digitalWrite(PIN_LED,HIGH);
  
  myPowSave.standby();

  //proceed after wakeup

}

void dummyfunc()
{}

Hi XIAO BLE Sense runs on a Nordic CPU core and throws
Arduino: 1.8.19 (Mac OS X), Board: "Seeed XIAO BLE Sense - nRF52840"

WARNING: library Seeed_Arduino_RTC claims to run on samd architecture(s) and may be incompatible with your current board which runs on nrf52 architecture(s).

Sorry, I don't have any answers. The document for RTC of nRF52 is here.
https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52832.ps.v1.1%2Frtc.htm