Hiya,
Turn the appliance off at the wall switch.
Ensure the rotary switch on the front of the appliance is set at the off position.
Switch the machine on at the wall and press and release the button, a cursor should move to the right with each press, once it's on the right hand side of the display, set the time using the rotary knob.
Once the time is set, press the button again.
If you find it won't work and the button makes a click sound, turn off at the wall and back on. Keep trying.
Hope this helps
Let me know how it goes.
Thanks
Home Appliance Technician
Whitegoods engineer working for a multibranded national company in the UK.