MS Teams机器人oAuthPrompt，如何更改弹出窗口大小

using Microsoft.Bot.Builder;
using Microsoft.Bot.Builder.Dialogs;
using Microsoft.Bot.Schema;
using System.Threading;
using System.Threading.Tasks;

public class AuthBot : ActivityHandler
{
    private readonly DialogSet _dialogs;
    private readonly IStatePropertyAccessor<UserState> _userStateAccessor;

    public AuthBot(UserState userState)
    {
        _userStateAccessor = userState;

        _dialogs = new DialogSet(userState.CreateProperty("DialogState"));
        _dialogs.Add(new OAuthPrompt(
            "OAuth Prompt",
            new TokenValidationParameters
            {
                ValidateIssuer = true,
                ValidIssuers = new[] { "https://login.microsoftonline.com/" }
            },
            "Please sign in",
            "Sign in",
            true,
            900,
            600));

        _dialogs.Add(new WaterfallDialog("mainDialog", new WaterfallStep[]
        {
            async (stepContext, cancellationToken) =>
            {
                return await stepContext.PromptAsync("OAuth Prompt", new PromptOptions { Prompt = MessageFactory.Text("Please sign in") }, cancellationToken);
            },
            async (stepContext, cancellationToken) =>
            {
                var tokenResponse = (TokenResponse)stepContext.Result;
                if (tokenResponse != null && !string.IsNullOrEmpty(tokenResponse.Token))
                {
                    // Handle successful authentication
                }
                else
                {
                    await stepContext.Context.SendActivityAsync("Authentication failed.");
                }
                return await stepContext.EndDialogAsync(cancellationToken);
            }
        }));
    }

    protected override async Task OnMessageActivityAsync(ITurnContext<IMessageActivity> turnContext, CancellationToken cancellationToken)
    {
        await _dialogs.RunAsync(turnContext, _dialogs.State);
    }
}