B-L072Z-LRWAN1 LoRa Board.Is PB12 available as SPI chip select?

Hi to all

At first let me say that i'm a newbie ,an old newbie.

I'm trying to add a SPI display to LoRa board based on

STM32L072CZ

I have used STM32CubeMx to select the pins,clock and so on,the programming enviroment is the AC6 Workbench,

i was encouraged to use the Hal libraries,and so i did.

Once the simple project was generated i added in the code a call to a simple blocking SPI function(despite i set SPI interrupt handler in Cube MX)

while (1)
 {
 Delay(10);
 HAL_SPI_Transmit(& hspi2, my_pdata, 4, 10);
 /* USER CODE END WHILE */
 /* USER CODE BEGIN 3 */
 }
 /* USER CODE END 3 */
}�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?

I can see the data and the clock,but the SPI_NSS pin PB12 stays low.

Does this mean that PB12 is not available?

If i check in the I/O register window ,PB12 results assigned to MODE2,as the other SPI2 pins are.

What can i do or check to understand the reason of this inactivity?

Thanks