ALL TRANSMISSIONS, TRANSFER CASES AND REAR DIFFERENTIALS ARE SHIPPED DRY.
YOU WILL NEED TO FILL IT WITH OIL!
Do not assume that just because there may be cap plugs fitted into the axle holes that the item is filled with oil. IT IS NOT FILLED WITH OIL. I install cap plugs to keep foreign material out of the unit and while there may be a small amount of oil in the unit from assembly and spin testing it is not enough for you to drive on.
You are to drain all oil before you ship it and you are to fill it with oil before you drive it.