launchCallUrl method
Implementation
void launchCallUrl(String _url) async {
  var phoneCall = await Uri.parse("tel:$_url");
  if (await launchUrl(phoneCall)) throw 'Could not launch $_url';
}void launchCallUrl(String _url) async {
  var phoneCall = await Uri.parse("tel:$_url");
  if (await launchUrl(phoneCall)) throw 'Could not launch $_url';
}