zentao/module/demand/js/submitreview.ui.js

window.changeNeedReview = function()
{
    const checked = $(this).is(':checked');

    $('[name^=reviewer]').zui('picker').$.setValue(checked ? '' : lastReviewer);
    $('[name^=reviewer]').zui('picker').render({disabled: checked});

    $(this).closest('.form-group').find('.form-label').toggleClass('required', !checked);
}