Question Ticket Advice for Wengen to Jungfrau Trip

Hi, I'm planning a trip from Wengen to Jungfrau and I'm a bit confused about the tickets. Do we need to buy separate tickets for the journey to Jungfrau and the return trip, or is there a round-trip option available? Also, if anyone has tips on the best way to purchase these tickets or any discounts to look out for, that would be super helpful. Thanks in advance for any advice!