Arduino for STM32

I have already been able to read/write on the EEPROM (EEPROM emulation) on STM32L433. However, for an unknown reason, I cannot put new data on EEPROM now where I only can read data using read command. I use EEPROM.h library and Arduino IDE for programming. It seems that the reserved page of the Flash is protected some how.
Does anybody know how to activate writing on EEPROM (Flash)?

Thanks in advance,

I could find a solution by using ST-Link Utility that worked for me as follows:
Run ST-Link Utility and connect to the microcontroller-->Target --> Optin Bytes --> Uncheck RCROP_RDP and Apply. If it doesn't work, change Level 0 to Level 1 and then come back to Level 0 again and apply the mentioned change. It erases the flash if it really applies the change. Disconnect STLink Utility and check out the modification. I hope it works for you too.

Best wishes

I used your recommendation and it worked for me. Thanks!