Intuitionism External Moral Order

Darwall defined the internalist conception in which rational intuitionists accept S's acceptance of a normative proposition as true only if they are moved by its truth. This immediately implies that since I have been exploring Ross for a while that if I follow Ross, I am committed to an external moral order of normative facts to which our intuitions are directed towards. It is this independent and external moral order that moves us through intuitions. However, I am wondering if I have to accept moral facts in this way, or is there another way to cash out the explanation for what our intuitions are about? Can intuitionism be a substantive theory without the requirement of mind-independent normative facts?