It will be necessary to anchor it to the bottom and, with that height, anchor it into the slope. Reinforce with at least 16 rebar per meter straight down into the ground, about 50 cm. At the top, rebar is attached to the wall about 30 cm down and goes straight into the slope, well anchored with 30x30 concrete slabs that the rebar goes through and bends on the back side. It is suitable for the anchor to be at least 1.5 meters in, depending on how the slope is.