The first thing I'd do is check the door seal, which is most likely the culprit 🚿 After 3 years it could've cracked, warped, or just accumulated dirt that prevents it from closing properly. Clean it with a damp cloth and see if you spot any cracks or parts that aren't fitting right. Sometimes there's detergent residue or limescale buildup preventing a tight seal, so a good cleaning can fix it without needing a repair.
If the seal is in good shape, then yeah, you'll need a technician. Could be the door latch has come loose (happens over time) or there's a problem with the locking mechanism. There's also a chance something inside the drum is damaged, but that's less common. A leak from the sides of the door almost always points to it not closing properly.
My recommendation is don't wait too long before calling the repair service if cleaning doesn't fix it, because if water keeps leaking you could end up damaging the floor or carpet, and that's a real expensive fix 😅 LG has a pretty solid reputation for service, so it should be relatively easy to sort out.