I Gusti Ngurah Rai International Airport, Denpasar: Amlapura has no airport or rail station. The sensible transfer is a pre-booked private car/driver direct from DPS; allow roughly 2.5–3.5 hours, longer in south-Bali traffic, and expect about Rp600,000–1,000,000 per car depending on timing and vehicle. Do not build an itinerary around a supposed airport bus connection: public transport is not a useful airport-to-Amlapura option.
Padang Bai ferry port: For arrivals from Lombok or the Gili islands, take the ferry/fast boat to Padang Bai, then arrange a driver onward to Amlapura. The road transfer is roughly 1.5–2 hours in normal conditions. Confirm the car before boarding the boat rather than accepting the first persistent offer at the port.
