I shift Volo 2015

I shift 12 speed volvo 2015
I no see the manual bottom the one
Makes the driver shift up or down
So how can I shift up or down
I drove before volvo 2014 I shift
It comes with manual control the little
Bottom shift up or down but this one no have .. is that safe if the truck have only auto shift specially when you climbing or steep down ?

 

before go steep down I'm trying
To move from 12 to 10 or 9 and I'm on the auto drive the only one I have it was hard need to keep brake and using engine brake and again during the steep down the transmission go's up 11 or 12
Because of transmission stay on auto
mood .. this is the thing happened with me