Dulux, I assume you’re in the UK/Australia/Canada. PPG owns the rights to the Dulux brand in Canada, while AkzoNobel has the rights to it in the UK/EU. You need an “adhesion” primer such as Insl-X Stix, if you’re in the US/Canada it can be had at any Benjamin Moore dealer or Ace. You need the equivalent to that. An oil-base primer can also work.

Sand the melamine/Formica with US320/400 grit, prime, sand again with US400 grit, dust and paint with a good waterborne alkyd - dunno what your country has but something similar to Ben Moore Advance or PPG Break-Through in the US/Canada. Sand in between the first and final paint coats.