Well its this plugin that you have "cordova-plugin-ionic-webview " .
This plugins should not be there in your wplms ionic project .
It looks like this command was not executed well enough :
cordova plugin rm cordova-plugin-ionic-webview
Please run the above command then re-run
cordova plugin list
to check installed modules .
After removing that plugin please run this command :
then generate app for ios and test it .
As far as I know this was the issue with the project when I checked your src folder .
Please try above recommended solution and I hope it will work this time .