not showing printing option

i have created an app using ionic to print a page but its not showing printing option

here is my Index code

"utf-8">
"viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no, width=device-width">
"manifest" href="manifest.json">
"lib/ionic/css/ionic.css" rel="stylesheet">
"css/style.css" rel="stylesheet">
"lib/ionic/js/ionic.bundle.js">
"js/ng-cordova.min.js">
"cordova.js">
"js/app.js">
"starter">
class="bar-stable">
class="title">Print
"ExampleController">
class="button" ng-click="print()">Print Webpage

and app.js is

var a = angular.module('starter', ['ionic', 'ngCordova']);
a.run(function($ionicPlatform) {
$ionicPlatform.ready(function() {
if (window.cordova && window.cordova.plugins.Keyboard) {
cordova.plugins.Keyboard.hideKeyboardAccessoryBar(true);
cordova.plugins.Keyboard.disableScroll(true);
}
if (window.StatusBar) {
StatusBar.styleDefault();
}
});
});
a.controller("ExampleController", function($scope, $cordovaPrinter) {
$scope.print = function() {
if ($cordovaPrinter.isAvailable()) {
$cordovaPrinter.print("https://www.nraboy.com");
} else {
alert("Printing is not available on device");
}
}
});

am getting these errors

Error: [$injector:modulerr] Failed to instantiate module ng-cordova due to:

Error: [$injector:nomod] Module 'ng-cordova' is not available! You either misspelled the module name or forgot to load it. If registering a module ensure that you specify the dependencies as the second argument.