We picked up an Anker 6 port USB charger for our cruise on the Fantasy -
https://www.amazon.com/dp/B00P93618...olid=1KZAAS3A6OM0X&psc=0&ref_=lv_ov_lig_dp_it. Prior to ordering, I contacted
DCL to make sure the device would be approved. They checked and it was. (no extension cords, no power strips, etc.) Each of the chargers were packed, just in case, but we used the cables with this charger. It sat on the desk during the cruise, and then on the table at the WDW hotel after the cruise.
Remember, the power is off to the outlets in the cabin / room if you are not there. You won't be cable to charge devices during the day if you are out and about.