XMLHTTPRequest doesn't worked with Cordova apps

I build and I emulate a test version of futur application. But I have a problem and I found different solution on stackoverflow but nothing worked for me.

I found the first solution to remove and re-install cordova-plugin-whitelist and after that put this <allow-navigation href="*" />

If you have an idea you saved my day. EDIT : I run nothing server for example on webapp localhost:8000 probably the problem is here ?