Fetch and Pull using Personal Access token

I'm trying to fetch and pull everytime a request come to the application. So basically im using my own username and password for the same as of now. But when i try to implement it with my personal access token, it throws error.

    var path = "my local drive path";
    using (var repo = new Repository(path))
    {
        FetchOptions options = new FetchOptions();
        options.CredentialsProvider = new CredentialsHandler((url, usernameFromUrl, types) =>
            new UsernamePasswordCredentials()
            {
                Username="xxxxx@yyy.com",
                Password = githubtoken //my personal token
            });

        foreach (Remote remote in repo.Network.Remotes)
        {
            IEnumerable<string> refSpecs = remote.FetchRefSpecs.Select(x => x.Specification);
            Commands.Fetch(repo, remote.Name, refSpecs, options, logMessage);
        }
    }
    //Console.WriteLine(logMessage);

    using (var repo = new Repository(path))
    {
        // Credential information to fetch
        LibGit2Sharp.PullOptions options = new LibGit2Sharp.PullOptions();
        options.FetchOptions = new FetchOptions();
        options.FetchOptions.CredentialsProvider = new CredentialsHandler(
            (url, usernameFromUrl, types) =>
                new UsernamePasswordCredentials()
                {
                    Username = "xxxx@yyy.com",
                    Password = githubtoken //my personal token
                });

        // User information to create a merge commit
        var signature = new LibGit2Sharp.Signature(
            new Identity("xxxx", "xxxx@yyy.com"), DateTimeOffset.Now);

        // Pull
        Commands.Pull(repo, signature, options);
    }

I tried replacing the token in place of the username and giving empty string in place of password. Still i'm getting the same error.

Beginne mit dem CredentialsHandler und UsernamePasswordCredentials, die an Commands.Fetch und Commands.Pull übergeben werden. Reproduziere fetch und pull mit den bereitgestellten Credential-Varianten, erfasse den genauen Fehler und ermittle das unterstützte Authentifizierungsverhalten für Personal Access Tokens; abgeschlossen ist die Aufgabe, wenn sich beide Vorgänge erfolgreich authentifizieren.