Congrats on getting them to seed! Starting seeds indoors is a great, low-cost way to grow your own food. It may take several attempts over years to get really good at this process, but it is well worth it in the end.
You should try to split these apart so that each plant is in it's own container. Jalapeños need a fair bit of space, maybe 15 inches (40cm) between each plant. If 2 jalapeños are planted within an inch of each other the output of each plant will be dramatically limited. Planting 30 or 40 plants this close would cause very few to grow into full plants and the output would be dramatically reduced.
I suggest preparing new small pots to "up pot" into with good moist medium. Water this pot thoroughly. Very gently, separate out the seedlings from the big pot and replant them into the small pots. Keep your eye on the plants for the first few days after up-potting to ensure they get good light/water (not too much nor too little of either of those). There is tons of advice online about this process in more depth, so be sure to tead a few guides and watch some youtube videos on up-potting jalapeño seedlings.