How to order axes of geom_tile heatmap with different colours in the upper and lower triangle?

I want to make a heatmap with different colours in the upper and lower triangles. This works as I expect:

How to remove space between tiles in geom tiles

I am trying to make a heat map using ggplot and geom_tiles using this code

How to remove space between tiles in geom tiles

I am trying to make a heat map using ggplot and geom_tiles using this code

How remove space between tiles in geom tiles

I am trying to make a heat map using ggplot and geom_tiles using this code