That's a local IP address, please do your own test, get a folder in MiXplorer and try to serve it with Webdav without wifi in your phone.
You are able to access your webdav storage from another machine over mobile data? Then I would use that app, mixplorer doesn't do that. Most cell phones companies make that almost impossible to do. Link us the apk file or the playstore link to the RCX app.