There are ATMs in larger areas. Some resorts are some distance from ATMs so it’s a good idea to visit while you are still at the airport after arrival. ATMs in Bali don’t take all cards so if you have multiple cards it’s good to have them as a backup, and be prepared to try withdrawing multiple times, as the onscreen menu can be bewildering and you may need to keep trying different options until one machine eventually dispenses your money.