Synchronous Xero like synchronous Google Ads?

Question

I believe that this piece of C# runs an async method as part of the OAuth2 process:

            // Authorize the user using desktop application flow.
            Task<UserCredential> task = GoogleWebAuthorizationBroker.AuthorizeAsync(
                secrets,
                scopes.Split(','),
                "user",
                CancellationToken.None,
                new FileDataStore("BOGoogle-" + credPathSuffix, false)
            );
            UserCredential credential = task.Result;

I understand that task.Result is starts that task and waits for it to finish.

So I though I would use the same approach with Xero as it also has an async auth process:

            XeroConfiguration XeroConfig = new XeroConfiguration
            {
                ClientId = ini.IniReadValue("Xero", "CLIENT_ID", ""),
                ClientSecret = ini.IniReadValue("Xero", "CLIENT_SECRET", "")
            };

            var client = new XeroClient(XeroConfig);

            var task = Task.Run(async () => { await client.RequestClientCredentialsTokenAsync(); });
            task.Start();
            task.Wait();
            IXeroToken token = null;// task.Wait(;

Now that's incomplete code but it's as far as I got to because I couldn't get the code to move beyond the Task.Run().

Is this even going to work? Obviously, I don't understand async/await and all that. Any clues on how to sync the async the way the Google Ads appears to be done.