In SC2, building is an ability. So you're looking for the action "Issue Order", and then you want to pick the order type "Order Targeting A Point" and the ability "SCV - Build Bunker".
Look at the picture I've attached.
Remember that you need to pick a point and a unit, which I haven't done here.
I tried Unit order and AI order to build a bunker, but it doesn't work. Worker just staying.
@AprilTaurus93: Go
In SC2, building is an ability. So you're looking for the action "Issue Order", and then you want to pick the order type "Order Targeting A Point" and the ability "SCV - Build Bunker". Look at the picture I've attached. Remember that you need to pick a point and a unit, which I haven't done here.