heatmap: x, y positions

using CairoMakie, Random

Random.seed!(123)
x = y = -5:1:5
z = [x^2 + y^2 for x in x, y in y]
fig = Figure(; size = (600, 400))
ax = Axis(fig[1, 1]; aspect = 1, xlabel = "x", ylabel = "y",
    xticks = x, yticks = y)
hmap = heatmap!(x, y, z, colormap = :Egypt)
Colorbar(fig[1, 2], hmap, label = "z values", width = 15, ticksize = 15,
    tickalign = 0.5)
colsize!(fig.layout, 1, Aspect(1, 1.0))
fig