Hi Frr and welcome to GoY. Is this some sort of fancy composter rather than a straight forward compost bin whether wood or plastic? Smelly compost indicates to me it is not rotting down properly, either because it is too wet or there is not enough solid matter in it. What do you actually compost?

Other useful tips are to layer your compost materials with soil every so often - just a spadeful will do, and if you have some nice rich soil, rotted leaves etc that would do fine. The idea is to get microbes up higher into the heap., and it does tend to keep it fresh. Some people add a little lime but don't do this if your garden is alkaline already.
Try to vary the kind of things you put into it so you get different textures - even shredded newspaper can help. If you put lawn mowings in don't over do it, and make sure you layer them with something coarser or with some soil.

If your present compost is really nasty I would tip it out and cart it to somewhere preferably away from the house or sitting area. If you have a veg plot or other empty area dig a trench and bury it and start again.
Hose off the affected grass area let it dry and see what it looks like.