Solve and plot Lorenz equations for two different initial conditions and two values of rho in julia

Question

My goal is to solve lorenz equations and plot them as it shows in the figure. I have two different initial conditions [x0, 1, 0] and x0= 0 then x0 =1* 10^-5 the two values of rho are ρ= 14 and ρ=28. I wrote this code in julia but I'm getting errors says "Got exception outside of a @test UndefVarError: u not defined lorenz_solver(x₀::Float64, ρ::Int64)" any idea on how to solve this issue enter image description here

using DifferentialEquations
using Plots
using LaTeXStrings

function lorenz!(t,p,u,du)
    x, y ,z = u
    sigma, ρ, beta = p
    du[1] = sigma*(u[2]-u[1])
    du[2] = u[1]*(ρ-u[3]) - u[2]
    du[3] = u[1]*u[2] - beta*u[3]
end

function lorenz_solver(x₀, ρ)
    u[0] = [x₀, 1, 0]
    tspan = (0.0, 100.0)
    p = [10, ρ, 8/3] 
    x₀, ρ = params
    prob = ODEProblem(lorenz!, u0, tspan, params)
    sol = solve(prob) 
    return sol
    #return the ODESolution
end

function lorenz_plot()
    params = [0, 14]
    sol1 = solve(prob)

    params = [1 * 10^-5 , 14]
    sol2 = solve(prob)

    p1 = plot(t, [sol1 sol2], ylabel=L"x1, x2", title="ρ = 14")
    p2 = plot(abs(sol1 - sol2), xlabel=L"t", ylabel=L"|x1 - x2|")
    p3 = plot(sol1, vars = (1,2,3), xlabel=L"x1", ylabel=L"z1")

    params = [0, 28]
    sol3= solve(prob)
   
    params = [1 * 10^-5, 28]
    sol4 = solve(prob)

    p4 = plot(t, [sol3 sol4], title="ρ = 28")
    p5 = plot(abs(sol3 - sol4), xlabel=L"t")
    p6 = plot(sol3, vars = (1,2,3), xlabel=L"x1")
    link=:all
    plot(p1, p2, p3, p4, p5, p6, layout(3, 2))
    #return the final plot
end

export lorenz_solver, lorenz_plot

end

I tied to execute this code in jupyter note to see what is the error but it shows no error