DIAGNOSIS The triple beep is the unit's safety interlock alert. One or both of the cooking baskets are not fully seated and locked into the base.
FIX Power the unit off. Remove both baskets. Visually inspect the metal connector pins on the bottom of each basket for any plastic shipping film or debris. Reinsert each basket into its designated slot. You must hear and feel a distinct, firm click when the handle is fully down. The unit will not operate without this lock engaged.
IF THAT DIDN'T WORK The issue may be the control panel's auto-shutoff from a prior error state. Unplug the unit from the wall outlet for a full 60 seconds. This resets the main control board. Plug it back in and attempt to lock the baskets again.
HEADS UP The left and right basket connectors are identical but the control system is not. Do not swap basket positions after setup, as this can confuse the independent temperature sensors.