Constrained Optimization Matlab

x = optimvar('x', 2, 1);

p = optimproblem();

p.Objective = x(1)^2+x(2)^2;

p.Constraints.C = x(1) + x(2) + 3 ==0;

[sol, fval, exitflag, output, lambda] = solve(p);

sol.x

lambda.Constraints