Own post-processing in URP

I'm trying to implement some own post-processing in URP. To do that I need to apply shader to rendered scene. I remember that was possible earlier with GrabPass, but I do not see such ability in URP. I've tried to use "Opaque Texture" flag in renderer's options. This way I was able to get rendered scene inside shader, but only objects rendered in Opaque queue. I need all objects from several layers, even Transparent ones. Is there way to achieve that in URP? Maybe I have to use RenderTexture? Thanks.