How to add background image with background environment and only render the first? im new to Blender so apologies for any silly question but I have an object that have already an HDR image as environment background for reflections and stuff, and now I want to composite that object with other image, how can I add the background image without rendering the environment background too?
If what you want to achieve is a render without the HDRI Background, you can go to Properties Panel > Render > Film > Transparent [x] []1

Another option could be going to Properties --> World --> Ray Visibility --> Uncheck the "Camera" Box.

Hopefully this is what you need, Cheers!