How can I write and overwrite random integers onto onboard EEPROM and then read the same saved value from onboard EEPROM for further processing on the stm32L072z LoRa sigfox discovery board?

Hello everyone,I have an STM32LO discovery board. Using it for a big project in IoT. How can i track the status of the onboard LED and write that data to the EEPROM? Say the led is on, saves that status and duration, then sends it as a packet to TTN....