The few times I’ve made it, I didn’t replace it with anything. I wouldn’t bother using pectin or gelatin. When egg is uncooked it won’t have a thickening effect, and that’s what you’re trying to match. So if the mix is too thick for your liking, add some water or apple sauce as others have said. But this is just for texture and thickness, to your liking.
The few times I’ve made it, I didn’t replace it with anything. I wouldn’t bother using pectin or gelatin. When egg is uncooked it won’t have a thickening effect, and that’s what you’re trying to match. So if the mix is too thick for your liking, add some water or apple sauce as others have said. But this is just for texture and thickness, to your liking.