Plot function in Non-linear optimization

%% Introduction to Constrained non-linear minimization

%Objective

fcn=@(x,y) log(1+3*(y-(x.^3-x)).^2+(x-4/3).^2);

%% plot

fsurf(fcn,[-2.5 2.5],'ShowContours','on')

view(127,38)

%% Create optimization

prob=optimproblem;

%% define variables

x=optimvar('x','LowerBound',-2.5,'UpperBound',2.5);

y=optimvar('y','LowerBound',-2.5,'UpperBound',2.5);

%% Define objective

prob.Objective = log(1+3*(y-(x.^3-x)).^2+(x-4/3).^2);

%% set optimization options

initialpt.x=-1;

initialpt.y=2;

options=optimoptions(prob,'Display','iter','OutputFcn',@plotUpdate);

%% solve the problem

[sol,fval,exitflag,output] = solve(prob,initialpt,'Options',options);

I am unable to get the @plotUpdate command working and thus, I do not get the contour plot with optimal x path. Could someone help me?