get png of a model without it's background

i’m wondering if it’s possible to get like a screenshot a Png file from a model fbx.
if yes, anyone know a good tutorial?

Where are you? In a game / build? In editor? Is a “fbx” model an actual streamed file, or an imported asset? What is “background”?

I will assume you are ingame and you are trying to get a texture with a screenshot of a prefab. What you can do is to have some disabled camera. Create a render texture and set it as camera’s target. Instantiate the prefab in front of the camera, call camera.Render(), destroy the prefab. Take the camera’s renderTarget texture and convert it to Texture2D or store it / use it where you need to.
If you want a transparent background, just set the camera’s clear mode to color, and set this color to something with zero alpha.