How to check order of accuracy of Euler forward

Is there a general code for how to check the accuracy order of Euler forward?

I have the odes:

odes = @(t,y) [0.272 -  0.00136*y(1) - 0.00027*y(1)*y(4); 
       2.7e-5*y(1)*y(4) - 0.00136*y(2) - 3.6e-2*y(2);
       2.43e-4*y(1)*y(4) + 3.6e-2*y(2) - 0.33*y(3);
       100*y(3) - 2*y(4)];

  
   for i=1:n
      y0(:,i+1)= y0(:,i)+dt*(odes(t(i),y0(:,i)));
      i=i+1
   end

with

   n=200;
dt=120/n;
t=0:dt:120;
y0 = [200; 0; 0; 4e-7];

How can I determine the order of accuracy?