Error: using fmincon with integral function

I am using integral and fmincon simultaneously but I am getting an error. I want to integrate magnitude wrt p and then optimize the objective function wrt to d.

%% Input
syms d p
G1 = 3e6

G1 = 3000000

G0 = 1.25e8;
V0 = 250;
k0 = p/V0;
V1 = 316;
k1 = p/V1;
 
 
%% Calculation
D = [cos(k1*d) sin(k1*d)*p/(G1*k1)*1i; sin(k1*d)*(G1*k1)/p*1i cos(k1*d)];
L = [2*p/k0*cos(5*k0) sin(5*k0)*2*p/k0*1i; sin(5*k0)*2*G0*1i 2*G0*cos(5*k0)];
B = D*L;
B1 = B(1,1);
B2 = B(1,2);
B3 = B(2,1);
B4 = B(2,2); 
 
Answer = (2*p*(B4-B3)-2*k0*G0*(B2-B1))/(k0*(B1+B2)*(B4-B3)-k0*(B4+B3)*(B2-B1));
magnitude = abs(Answer);
  
I = matlabFunction(amgnitude,"Vars",[p d]); 

Unrecognized function or variable 'amgnitude'.

 
options = optimset('PlotFcns',@optimplotfval);
d0 = 0.5;
A = [];
b = [];
Aeq = [];
beq = [];
lb = 0;
ub = Inf;
nonlcon = [];
[s,fval] = fmincon(integral(I,0,10),d0,A,b,Aeq,beq,lb,ub,nonlcon,options); %minimize

Answer 1

[Walter Roberson]

%% Input
syms d p
G1 = 3e6

G1 = 3000000

G0 = 1.25e8;
V0 = 250;
k0 = p/V0;
V1 = 316;
k1 = p/V1;
 
 
%% Calculation
D = [cos(k1*d) sin(k1*d)*p/(G1*k1)*1i; sin(k1*d)*(G1*k1)/p*1i cos(k1*d)];
L = [2*p/k0*cos(5*k0) sin(5*k0)*2*p/k0*1i; sin(5*k0)*2*G0*1i 2*G0*cos(5*k0)];
B = D*L;
B1 = B(1,1);
B2 = B(1,2);
B3 = B(2,1);
B4 = B(2,2); 
 
Answer = (2*p*(B4-B3)-2*k0*G0*(B2-B1))/(k0*(B1+B2)*(B4-B3)-k0*(B4+B3)*(B2-B1));
magnitude = abs(Answer);
  
I = matlabFunction(magnitude,"Vars",[p d]); 
 
options = optimset('PlotFcns',@optimplotfval);
d0 = 0.5;
A = [];
b = [];
Aeq = [];
beq = [];
lb = 0;
ub = Inf;
nonlcon = [];
[s,fval] = fmincon(@(d)integral(@(p)I(p,d),0,10),d0,A,b,Aeq,beq,lb,ub,nonlcon,options); %minimize

Local minimum found that satisfies the constraints.

Optimization completed because the objective function is non-decreasing in 
feasible directions, to within the value of the optimality tolerance,
and constraints are satisfied to within the value of the constraint tolerance.