Unfortunately, charter flights do not fly to Indonesia, and in the form we are used to buying, "last minute trips" will no longer be available. Even if you turn to a tour operator for a ready-made tour package, which already includes accommodation, transfers and, most importantly, air tickets, you probably overpay several times. Only regular flights fly to Indonesia, because the flight takes an average of 24 hours. From that, the prices for the flight have always been a bit "biting". Therefore, the best way is to independently search for tickets for these regular flights, so as not to overpay the same tour operators.
And of course, it’s better to do this in advance: firstly, ticket prices change very often, and secondly, as already mentioned earlier, many airlines often offer promotions and discounts, which increases your chance to purchase tickets at a very competitive price.