Control of the GPIO

I have some difficulties to control the GPIO of my BPI M2+(H3). I bought the Banana Pi Cookbook and I follow the instructions of the chapter 5: Using the GPIO pins. I installed WiringBP succesfully but then when I try the commands “gpio mode x OUTPUT” and “gpio write x 11”, nothing happen. When I use gpio readall, it seems that the GPIO selected is still on mode IN. Do you have any clue that might help me? + works.