How to turn off objects environmental adjustments

I’d like to add a greenscreen in my UE environment. For that I need a completely green surface without any reflections oder shadows on it. I want to turn of all the environmental adjustments from unreal engine. Does somebody know how to turn them off, to have a super green surface, in every angle, room or atmosphere?
Thank for you reply

Unlit material:

I assume that’s it, but could be wrong. Probably good to also look at something like