Printed part does not stick on the heated bed

[rahul]

As has been stated, many things could cause this. Start by releveling your bed, the enclosure idea is a good one, any draft can cause issues. My Ender 3 Pro is in one of these https://www.creality3dofficial.com/p...y-installationCooking with Raahul

Great thanks for sharing information

[curious aardvark]

what temps are you printing at ?
you don't even say what filament you are using.

Quite often all you have to do is slow the first layer print speed down.