C# Youtube channel list API is throwing Insufficient Permission [403]

Question

The credential json I have received was in this format:

{
    "token": "test token",
    "refresh_token": "test refresh",
    "token_uri": "test uri",
    "client_id": "test client id",
    "client_secret": "test client sec",
    "scopes": ["https://www.googleapis.com/auth/youtube.readonly", "https://www.googleapis.com/auth/youtubepartner", "https://www.googleapis.com/auth/yt-analytics-monetary.readonly", "https://www.googleapis.com/auth/yt-analytics.readonly"]
}

It was throwing the error:

"Could not cast or convert from System.String to Google.Apis.Auth.OAuth2.GoogleClientSecrets"

I wrapped it inside {"web":{json}} and tried, but now it's throwing:

Google.Apis.Requests.RequestError - Insufficient Permission [403] Errors [Message[Insufficient Permission] Location[ - ] Reason[insufficientPermissions] Domain[global]]}

I am using following scopes

YouTubeAnalyticsService.Scope.YtAnalyticsReadonly, YouTubeAnalyticsService.Scope.YtAnalyticsMonetaryReadonly, YouTubeService.Scope.YoutubeForceSsl, YouTubeService.Scope.Youtube

while creating credential, but now, it's breaking at .Execute()

YouTubeService youtubeService = AnalyticsLoggingHelper.GetYoutubeService(channelinfo);
var channelResourcesList = youtubeService.Channels.List("contentDetails");
channelResourcesList.Id = channelinfo.ChannelId;
var listResult = channelResourcesList.Execute();