If the widget doesnt offer an option to switch then sadly there is not much to be done about it. You will have to create your own widget or try and look for one that does support that. Sadly web barcode scanners are not that good yet compared to native scanners because they rely on the possibilities of the browser. If you do go the custom widget route I recommend https://github.com/briosheje/react-html5-qrcode-reader react library. So far the best one I’ve used.
You can also try submitting a support ticket in the Mendix support portal but not sure if this issue falls under their support.