Making Audio sound like it's behind you in a text game

I have a text adventure game where I have sounds and background sounds. How can I get a sound to play from behind you if the person is wearing 7.1 headphones?

I tried the Microsoft Spatializer but can't seem to get it to work even when I move around the Planner values. https://assetstore.unity.com/packages/tools/audio/microsoft-audio-spatializer-116094