Using Displacement For Texture Decals

I am trying to implement displacement into a texture decal to make it look like it is sinking into a wall for a natural look.
I had a read on Parallax Occlusion Mapping for texture decals, and I have learnt that I need to use mesh decals instead of being able to do it on a normal deferred decal and place it on the map.

I have no clue on where to start, at least I know that I will have to spawn the decal in with a spawnable blueprint, but I do not know how to make a material for a decal with Parallax occlusion mapping

This is the broken wall decal I am trying to do it on