An Undefined Function error was thrown on the workers for 'gen_user'

Please I am using the d2d simulator and I am having issues with a portion.

spmd
for i=1:LOOP
    % generate user drop
    for idx = 1:7
        users_pos = gen_user([0,0], N_USER, ISD);
        
        % generate d2d pair drop
        [d2d_tr, d2d_rc] = gen_d2d_pairs([0,0], d2d_range, N_USER, d2d_radius, ISD);
        
        % generate single cell interference                        d2d_tr, d2d_rc, d2d_tp, cue_pos, cue_tp, n, isd, s, isLOS, freq)
        [d2d_throughput, cellular_throughput] = cal_throughput_ILA(d2d_tr, d2d_rc, PTOTAL, users_pos, PTOTAL, N_USER*N_SEC, ISD, FREQ, pathloss_parameters(idx));                     

        d2d_throughput_tmp(idx) = d2d_throughput_tmp(idx) + d2d_throughput;
        cellular_throughput_tmp(idx) = cellular_throughput_tmp(idx) + cellular_throughput;
    end
end
end