sounds like drain/gravity problem. your drain outlet hose must be higher than the tub in the washer, like a clothes washer is. if it’s not water will run straight thru.
If it’s not filling by its self, then the shut off solinoid is bad, (where the water line connects to the machine), this opens lets water in shuts off when the float reaches proper height.
The flost is in the tub area where you load dishes, it should be free to “bob” up and down, it may be stuck and not letting water in.