Hackers Help: Please, need advice painting the BESTÅ

besta shelf unit with doors
besta-shelf-unit-with-doors-white__0248526_PE387026_S4
Photo: IKEA.com

Hi, I want to paint a BESTA furniture because it’s not in the colors I want. So I bought some paint and tried to apply the paint on the furniture. The problem is, went the paint is dry, if I scratch it with my nail it comes off. It’s like the paint is not adhering to the furniture.

Anybody can help me? Do I need to buy a different paint or a primer to apply on the furniture before painting?