Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f3/STM32F301/ADC/OFR2#0x0
ADC offset register2
Data offset 2 for the channel programmed into bits OFFSET2_CH
Channel selection for the Data offset 2
Offset 2 Enable
https://github.com/modm-io/cmsis-svd-stm32