Arduino for STM32

I am designing a digital meter with STM32F401RE. I want save some data to flash memory in case of power failure . I tried this tutorial https://www.youtube.com/watch?v=i2YsKacRZOs&t=2s but it's not working. Should I do this with a battery? If not, what is the best to do it

bests.

Hello guys,

I am trying to work with STM32l562E-DK and STM32duino, but when I flash the MCU, the serial monitor shows me nothing. Is this device supported? What could be the problem?

thanks in advance
Bests