Youtube API订阅失败

Question

我的问题是试图准确确定我需要做些什么来为用户添加订阅。

我将这些脚本添加到我的html

<!-- Youtube platform start -->
<script type="text/javascript" src="https://apis.google.com/js/platform.js"></script>
<script type="text/javascript" src="https://apis.google.com/js/client.js?onload=googleApiClientReady"></script>

我的脚本如下：

            // Get browser location
            $scope.currentUrl = window.location.origin + window.location.pathname;

            // get Channel Id
            var channelId = CHANNEL_ID_HERE;

            // Call to Youtube API for channel thumbnail, name, description, and subscribers
            $http({
                method: 'GET',
                url: 'https://www.googleapis.com/youtube/v3/channels?part=statistics,snippet&id=' + channelId + '&key={API_KEY}'
            }).then(function successCallback(response) {
                console.log(response);
                $scope.channelThumbnail = response.data.items[0].snippet.thumbnails.default.url;
                $scope.channelName = response.data.items[0].snippet.title;
                $scope.channelDesc = response.data.items[0].snippet.description;
                $scope.channelSubs = response.data.items[0].statistics.subscriberCount;

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

            function initClient() {
                gapi.client.init({
                    apiKey: 'API_KEY',
                    clientId: 'CLIENT_ID',
                    scope: 'profile',
                }).then(function () {
                    console.log("gapi initialized");
                });
            }

            gapi.client.load('youtube', 'v3', initClient);

            $scope.addSubscription = function () {
                var resource = {
                    part: 'snippet',
                    snippet: {
                        resourceId: {
                            kind: 'youtube#channel',
                            channelId: channelId
                        }
                    }
                };
                var request = gapi.client.youtube.subscriptions.insert(resource);
                request.execute(function (response) {
                        var result = response.result;
                        if (result) {
                            alert("Subscription completed");
                        }
                        else {
                            alert("Subscripion failed");
                        }
                    }
                );
            }

请假装clientID和ApiKeys在那里。当我调用addSubscription函数时，这是发出的调用：https://content.googleapis.com/youtube/v3/subscriptions?part=snippet&alt=json&key=APIKEY。我没有正确地初始化某些东西，还是还有其他东西需要完成这个POST？我已经阅读了很多文档，但似乎无法找到原因并不会成功。我的GET请求工作得很好，但我似乎无法获得POST请求。

提前致谢。