<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

var headers = {}
 this.http.setDataSerializer('json')
 return this.http.post(API_URL, send_data, {headers: headers})
  .then(data => {
 ...
 }

<access origin="*" />
<access origin="*" subdomains="true" />
<allow-navigation href="http://*/*" />
<allow-navigation href="https://*/*" />
<allow-navigation href="localhost:8080" />
<allow-navigation href="data:*" />
<allow-intent href="http://*/*" />
<allow-intent href="localhost:8080" />