Communicate with the LOD. Let them know your CA is a NCNS. Sometimes things just simply don't get communicated. I've seen more than a few times where I'll call the LOD about a NCNS and be told, "Oh, I'm sorry, I forgot to tell you."
Come up with a plan. Know who has experience on carts, maybe you can send them outside (providing you have enough help)
depending on your store/LOD you may be told what you're going to do, or your LOD may expect you to know your team and who can do carts.
You may have to go out yourself.
One of our cart attendants has health issues, so I've been in the situation many times when I've had to scramble for a cart attendant, or if I had two GSAs, I would end up outside.