How do I place objects on a grid?

I'm making a mobile game and I want to be able to place blocks side by side without them overlapping.

I have tried "On Tap -> Create object at Touch.X and Touch.Y" but it places it exactly where I tap which causes them to overlap.

Some info that might be useful: I am not using a tilemap. The viewport is 720x1280. The objects I'm trying to place are 128x128.

You can use this method:

This worked beautifully! Thank you!