The most fuel you can start with for this payload without going over MTOW or the 5,400 lb max fuel.
The aircraft list and weights are locked. Enter the fleet code once on this iPad and it stays unlocked, even with no signal.
Max start fuel = (MTOW − final operating weight − payload) + 45 kg taxi, × 2.205 for lb (rounded down), but never more than the 5,400 lb max fuel. Payload must also keep the zero fuel weight under MZFW. Check against your load sheet.