ionicframework setting up international-phone-number directive

Am learning ionic and I want to use this directive international-phone-number direcrive. I have linked the file on my index.html page

<script src="lib/international-phone-number/releases/international-phone-number.js"></script>

and in my view used one of the default examples from the link <input type="text" international-phone-number only-countries="pl, de, en, es" default-country="pl" preferred-countries="pl, de" ng-model="phone">

the directive is not working for me , what could I be doing wrong?