My first try CairoMakie.jl

abline_makie.jl

using Random
using Distributions
using CairoMakie
using FileIO

beta = [1, 2]

rng = Random.default_rng(1234)
X = [ones(10) randn(rng, 10)]
y = X * beta + randn(rng, 10)
betahat = X \ y


fig =Figure()
ax = Axis(fig[1, 1])
scatter!(ax, X[:,2] , y)
line1 = ablines!(ax, beta[1], beta[2])
line2 = ablines!(ax, betahat[1], betahat[2], color = :orange, linestyle=:dash)
Legend(fig[1, 2],
    [line1, line2],
    ["true", "fitted"])

fig
save("abline.png", fig)