They’re failing because you’re doing everything wrong. Not trying to be mean, just honest. 1 seed per cup, you need drain holes in the bottom and air circulation up top so lose the domes, poke some holes and pull one out of each cup, should be salvageable but if not and you have plenty of seeds just start over and do it right, you can even re use the cups just make sure you poke a bunch of holes in the bottom for drainage. You’re probably overwatering too, and if you’re in an inert media (peat or coco) you need to fertilize, gh maxigro/bloom is probably the cheapest and easiest option since they’re complete one part fertilizers.