Remove plug and left hand side panel. Flow meter is located at the bottom of the water chamber. Standard fault is oxidisation of the contacts – remove connector, clean contacts, give the connector a squeeze and refit. 9 out 10 that will cure it.
It’s a decent enough machine, worth a few more checks……
Does it take on any water at all? If NO, check the water valve at the back – coil should read approx 3.5kOhms when split from the circuit. If it does fill, but faults, it’s possible that the flow meter itself is faulty and the fill chamber may need to be replaced.