How to use Cross Origin Sharing in Cordova

I am building a Cordova that uses jQuery AJAX for accessing our backend API. Whenever I try to access the backend I get the following error:

Access to XMLHttpRequest at 'https://testsite.com/' from origin 'http://localhost:8000' 
has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the 
requested resource.

I know this is a common problem, and there are many solutions here and all over the web, but none of them seem to help solve my problem.

My confix.xml is:

<content src="index.html" />
<plugin name="cordova-plugin-whitelist" spec="1" />
<access origin="*" />
<allow-intent href="*" />
<allow-navigation href="*" />


<platform name="android">
    <allow-intent href="market:*" />
    <config-file parent="/*" target="AndroidManifest.xml">
        <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
        <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
        <uses-feature android:name="android.hardware.location.gps" />
        <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.CAMERA" />
        <uses-feature android:name="android.hardware.camera" android:required="true" />
        <uses-permission android:name="android.permission.INTERNET" />
    </config-file>

</platform>

package.json:

"cordova-plugin-whitelist": "^1.3.4",
"cordova": {
    "plugins": {
        "cordova-plugin-file": {},
        "cordova-plugin-camera": {},
        "cordova-plugin-whitelist": {}
    },
    "platforms": [
        "browser",
        "android"
    ]
}

And my meta tag is currently:

<meta http-equiv="Content-Security-Policy" content="default-src *; style-src 'self' 'unsafe-inline'; script-src * 'unsafe-inline' 'unsafe-eval'; img-src 'self' data: blob: ;" />

I am getting this error in Chrome and Android. If anyone has any ideas about what I might be doing, they would be greatly appreciated