.net core 3.1 : How to get to new token using AcquireTokenAsync method if access token is expired?

My client application i.e. webchat uses openid authentication and generated access token is also passed to bot to use while calling graph apis.

start up Code:

 services.AddAuthentication(options =>
        {
            options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
            options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
            options.DefaultSignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        })
        //.AddAzureAd(options => this.Configuration.Bind("Authentication:AzureAd", options))
        .AddCookie()
        .AddOpenIdConnect(options =>
        {
            options.ClientId = "cid";
            options.ClientSecret = "csercet";
            options.Authority = string.Format(azureAdConfig.Instance, azureAdConfig.TenantId);
            options.ResponseType = OpenIdConnectResponseType.CodeIdToken;
            options.Resource = "https://graph.microsoft.com/";
            options.Events = new AuthEvents(azureAdConfig);
        });

Once Authorization code is recieved in authevents then Access Token is generated :

    public override async Task AuthorizationCodeReceived(AuthorizationCodeReceivedContext context)
    {
        var principal = context.Principal;
        var request = context.HttpContext.Request;
        var currentUri = UriHelper.BuildAbsolute(request.Scheme, request.Host, request.PathBase, request.Path);

        var tokenService = (ITokenService)context.HttpContext.RequestServices.GetService(typeof(ITokenService));
        try
        {
            var x = await tokenService.RequestTokenAsync(principal, context.ProtocolMessage.Code, currentUri, "https://graph.microsoft.com/")
                 .ConfigureAwait(false);
            context.HandleCodeRedemption(x.AccessToken, x.IdToken);
        }
        catch (System.Exception ex)
        {               
            throw;
        }
    }

 result = await authContext.AcquireTokenAsync(resource, "clientid", new Uri(redirectURI), new PlatformParameters(PromptBehavior.RefreshSession, null));

Parameters class :

    #region Assembly Microsoft.IdentityModel.Clients.ActiveDirectory, Version=5.2.8.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
// C:\Users\v-sagkul\.nuget\packages\microsoft.identitymodel.clients.activedirectory\5.2.8\lib\netstandard1.3\Microsoft.IdentityModel.Clients.ActiveDirectory.dll
#endregion

using Microsoft.IdentityModel.Clients.ActiveDirectory;
using Microsoft.IdentityModel.Clients.ActiveDirectory.Extensibility;

namespace Microsoft.IdentityModel.Clients.ActiveDirectory
{
    //
    // Summary:
    //     Additional parameters used in acquiring user's authorization.
    public class PlatformParameters : IPlatformParameters
    {
        //
        // Summary:
        //     Constructor that allows extends to configure their own web ui. Not implemented
        //     on Android, iOS and UWP.
        //
        // Parameters:
        //   promptBehavior:
        //     Controls the prompt that is displayed on web ui. Default is Microsoft.IdentityModel.Clients.ActiveDirectory.PromptBehavior.SelectAccount.
        //
        //   customWebUi:
        //     Custom implementation of the web ui
        //
        // Remarks:
        //     This object is platform specific and should not be constructed from NetStandard
        //     (shared) assemblies.
        public PlatformParameters(PromptBehavior promptBehavior, ICustomWebUi customWebUi);

        //
        // Summary:
        //     Gets the configured prompt behavior
        public PromptBehavior PromptBehavior { get; }
        //
        // Summary:
        //     Extension method enabling ADAK.NET extenders for public client applications to
        //     set a custom web ui that will let the user sign-in with Azure AD, present consent
        //     if needed, and get back the authorization code.
        public ICustomWebUi CustomWebUi { get; }
    }
}