Brush the outside with a vegetable scrubber to remove dirt. Run the sweet potato under running water, brushing off dirt and other particles with your hands. Pat it dry with a clean towel. Leave the skin on for additional nutrients. For this reason, buy pesticide-free sweet potatoes if possible. Prepare a sharp knife or mandolin. Use the mandolin on the thinnest setting, or slice the sweet potato into rounds that are one-sixteenth to one-eighth inch (0.16 to 0.3cm) thick. A mandolin is ideal, because it will ensure all the rounds are the same thickness, which means they’ll dehydrate at the same rate. To use a mandolin, press the top of the sweet potato to the mandolin slicer and move in a downward motion, slicing the sweet potato rounds until you reach the end of your potato. Use the vegetable holder to ensure you don’t cut your hands on the sharp mandolin. Fill a large bowl full of fresh, room temperature water. Soak the sweet potato slices for one to two hours. The starch in the sweet potato will prevent moisture from escaping, but soaking will help remove some of the starch, leading to crispier sweet potato chips. You can change the water halfway through the soaking process, but this step is not necessary. When they are finished soaking, remove the sweet potato rounds from the water and place them on a clean towel or paper towel. Pat them completely dry before dehydrating. Transfer the sweet potato rounds to a large plate. Brush them with olive oil or melted coconut oil. Alternatively, place the sweet potato rounds into a bowl, drizzle with oil, and toss to coat. Oil is not necessary to dehydrate sweet potatoes, but it will result in crispier chips. You can make your sweet potato chips sweet or savory, and add any seasonings you desire. You can try:  Himalayan or sea salt Black pepper or cayenne pepper Cinnamon  Rosemary or thyme Onion powder or smoked paprika

TL;DR in Indonesian:
Cuci ubi jalar. Iris ubi jalar. Rendam irisan ubi jalar. Keringkan irisan ubi jalar. Tambahkan minyak. Bumbui irisan ubi jalar.