As per the author comment you need to set the position relative to container and set the container as popup container, there is property called getPopupContainer
in this plugin.
like this
<div id="testPosition" style={{ position: 'relative' }}> hello<Select getPopupContainer={() => document.getElementById("testPosition")} style={{ width: 100 }}><Option value="jack">jack</Option><Option value="lucy">lucy</Option><Option value="yiminghe">yiminghe</Option></Select></div>