Question Project grid onto meshes

Hey folks! I've got a newbie question for you. I've got terrain / meshes being procedural generated in 3D on a 16 x 16 grid; imagine the terrain in Transport Tycoon or Parkitect. This is built at runtime using C# by creating individual tile meshes which looks and works great. So my next step is, how would I go about drawing or projecting a grid onto the terrain? I'd quite like the grid to be "toggleable", so I don't really want to bake the grid into the terrain materials if possible. It's worth noting I'm using URP.

Thanks in advance for any help!