Stm32duino Low power library not working on platformIO

im experiencing same issue as this: the code compiles but while compiling it throws a warning like this .pio\libdeps\genericSTM32F103C8\STM32duino RTC\src\STM32RTC.cpp:160:2: warning: #warning "only BCD mode is supported" [-Wcpp] 160 | #warning "only BCD mode is supported" | ^~~~~~~
i dont know if that has anything to do with the library not working. im using the timed wakeup example on stm32f103c8. does annyone know how to fix this problem? LowPower.deepSleep(2000); does not work at all