Unrecognized function or variable in parfor in MATLAB

Question

I am a beginner in MATLAB software and I use MATLAB online .The problem is in initializing a variable called 'estModel' in a parallel loop . I want to use parallel processing because the calculations take a long time to complete but this problem occurs when I use 'threads' in parpool instead of 'local' . In 'local' mode this problem does not exist and the code is executed correctly and the results are correct . But in the case of 'threads', the variable 'estModel' is not initialize in the parfor loop , and give this error : Unrecognized function or variable 'estModel' . In 'local' mode the number of workers are 2 but in 'threads' mode the number of workers are 8 . So I use 'threads' instead of 'local' . I do not know about parpool structure completely . Is there a problem in this part ( parpool : local or threads or ... and chooses 'threads' based on the number of workers ) ? Finally the three variables 'kh', 'model' and 'DATA' are completely initializing before parallel loop and the variable 'model' uses the arima function . Can anyone help me to solve this problem?

code :

clear all;
close all;
clc;
DATA=xlsread('test');  % The data for modeling and forecasting is read from an excel file called test, which is a column vector.
size_of_DATA=length(DATA);
p=20;  % nonseasonal autoregressive polynomial degree range in arima model.
q=10;  % nonseasonal moving average polynomial degree range in arima model.
D=2;   % degree of nonseasonal integration range in arima model.
h=0;   % counter
for k=1:D
    for j=1:q
        for i=1:p
            if i+j+k-2<=size_of_DATA
                h=h+1;
                model(h)=arima(i-1,k-1,j-1);
            end
        end
    end
end
poolobj=parpool('threads'); 
parfor i=1:h
    estModel(i)=estimate(model(i),DATA);
end
delete(poolobj);

The excel file called 'test' is an arbitrary time series that is a column vector with 500 datas (of course, its length can vary). you can use file in this link for test : ln5.sync.com/dl/9e3913140/ctiyajcx-mgmnis6z-8mgyaigq-p2a9hpxu