I am using above settings and functions for RTC and One Alarm, also attached with this post as RTC_and_One_Second_Alarm_Setup_using_STM32hxxx.pdf, please review and let me know if you see any issue. Thanks in Advance.
I recommend you, when you configure the RTC Alarm with interrupt using STM32CubeMX, to follow the steps shared in Getting started with RTC - stm32mcu Wiki. The aim of this wiki is to explain how to setup RTC with interrupt in STM32CubeIDE and how to create a simple RTC project with periodic alarm interrupt.