If it's got one, it's on the front of the machine. Normally a small door covering it or the plinth comes off to reveal it.
If you can't find it, go to the Whirlpool website and get the instruction manual for it.
BTW, a blocked filter doesn't make it leak, it just won't drain.
As sleepyhead said I think you will find the filter behind the bottom front plinth. You can access it by putting a small screw driver between the bottom of the body of the machine and the top of the plinth/kick plate. Alternatively it should drop down if you place each hand at the plinth top and tilt forward. You should find the access to the filter behind here.Also as sleepyhead pointed out if the filter is blocked it will just stop the machine from draining it will not cause water leakage. To find a leak the technician would have to take the front off for further inspection of were the water is dripping from.
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