How can i make a script that generates like a "ghost" tile map

Hello, i found a video where there is a tile map generated, altough it doesnt have any mesh or anything in it, it just show a infinite map like a plane (i will attach a pic of what i mean). I can only think of making a gigantic custom plane and finding a way to attach my tiles prefabs later on it, the thing is that once the plane is made, i would have to manually correct the position of each tile, so it fits good on it.

So the final question is, how can i generate this kind of ghost map and make it so that when i place a tile on it, it fits perfectly on it, without having to move them (not sure if pivot is the right term).

Thanks in advance Image of the map

Solved by generating the mesh of a giant plane (?)