<input type="text" ng-model="data.username">
<input type="text" ng-model="data.password">
<button ng-click="login ()">Login</button>

---------------------

$scope.login = funtion(){
$scope.data = {};
$http({
        method: 'GET',
        headers: {
          username: $scope.data.username,
          password: $scope.data.password,
          'Accept': 'application/json'
        },
        timeout: 15000,
        url: 'urlnya'
      }).then(function successCallback(response) {

		console.log(response.data); // Dapet Key

},function errorCallback(response) {
        console.log(response)

      });

}