The function mx.ui.action no longer exists in the React Client API of Mendix 10.6, instead it needs to call mx.data.action like you already found.
You can check with the publisher of the widget (Emixa) to see if they are willing to provide support/update on the widget. If they won't, you can look up the source code on GitHub https://github.com/appronto/ScanBox, fork it and create your own version of the widget (I believe that the license is permissive enough to let you do that, but im not a lawyer ;)
(Personally I try to avoid widgets that only have a version 1.0.0 and no updates, this already introduces a risk since the widget was never updated since initial release)