Whirlpool Dishwasher flowmeter failure?

I’ve bought a secondhand Whirlpool dishwasher which I have been assured was working when removed from a kitchen but when I try to start it it begins to fill then starts bleeping and empties then stops. It is flashing 7 times which I believe is the code for flowmeter failure. Not sure where the flowmeter is.
Any advice about this problem would be appreciated.
Thanks
Fraser.

Please check your Model Number

The only units that come up are a couple “ADG” Gas dryers.
I tried a couple different sites.
It does not come up at all on the Whirlpool site.