you will have to google from the looks of it, or use logical approach
1. Did you leave a sock behind?
2. a coin stuck in the pump,
3. well that was joke.
Do you know if your pressure sensor (I call it pressure sensor but in WM industry it may be called something else) it is a sensor that when your drum fills up with water and when water level reaches nominal height, the sensor trips in causing the water taps (Solenoid controlled water inlet tap or valves or whatever anyone care to call it, doesn't effect its function, you can call it a critical pressure reactor if you like) closes, and the machine cycle begins.
When it had gone through various cycles, the last cycle is rinse and spin dry, and if the machine still beeps it may mean that water has not drained completely, even if it has, but the sensor (pressure sensor) is still engaged as if the drum has not completely emptied, this happens when small plastic tubes leading from the pump housing to this diaphragm operated pressure switch/sensor has a strange blockage with soap suds and slimy deposit build up, and it can plug this pipe such that it can allow water to enter and rise in the tube as water fills up the drum, but then fails to drop down when water is emptied, the obstruction caused by this gunge or plug moves up and down making it sort of one way flow, this tube should be completely clear of any obstruction.
However, I might be wrong above, when this happens usually the machine door won't unlock, so does your door open after a couple of minutes when wash cycle finishes, or do you actually switch the machine off in which case the door will open after the timed lock (thermal lock) cools down. But if you do not switch off machine from mains, and the beeps keep on going , and the door open light does not come on, then you definitely have a blockage in this tube.
The diaphragm pressure switch is usually mounted higher up the machine just under the top lid, so if you can remove this top, and locate this pressure switch, remove the plastic or rubber tube from it and blow through the tube, can you hear any bubbles from the pump housing,? if so then that indicates the tube is clear of any obstruction and problem is something else, I can't think of anything else apart from a stuck sock!
Different machines have different pressure types of pressure sensors/switches, some have a simple one set of contacts, others may have multiple stage contacts, but all look similar round about 3 inch diameter roughly, and have a connector with several wires connected to it, before you open top lid, Kill MAINS as dangerous voltages are everywhere.
Also if this tube gets blocked, where no water can get up it, your machine can then flood the whole kitchen as the switch won't know when to stop the filling taps.