Active directory Invalid token in xamarin forms - xamarin.forms

Question

I am developing a small application using Xamarin forms, I would like to implement (MSAL) active directory, I have configured everything and getting token, after that I have checked in postman while I am getting below
{"success": false," message": "Sorry, you are not authorized to access this API. Please make sure you are logged in!","data":null}
I tried sending the web request to server while I am getting HTTP response below
{StatusCode: 401, ReasonPhrase: 'Unauthorized', Version: 1.1, Content: System.Net.Http.HttpConnection+HttpConnectionResponseContent, Headers: { Transfer-Encoding: chunked Server: Kestrel WWW-Authenticate: Bearer error="invalid_token", error_description="The signature is invalid" X-Rate-Limit-Limit: 12h X-Rate-Limit-Remaining: 4999 X-Rate-Limit-Reset: 2021-07-19T14:20:05.8546118Z Date: Mon, 19 Jul 2021 02:20:05 GMT Content-Type: text/plain }}
Here I tried the code below, please help me to resolve this issue
App.xaml.cs
public static IPublicClientApplication PCA = null;
public static string[] Scopes = { "User.Read" };
PCA = PublicClientApplicationBuilder.Create(Constants.ClientID)
.WithRedirectUri($"msauth://{Constants.AppId}/{Constants.SIGNATURE_HASH}")
.WithAuthority($"https://login.microsoftonline.com/{Constants.TenentID}")
.Build();
Viewmodel signin command i called SignInAsync
public async Task SignInAsync()
{
Microsoft.Identity.Client.AuthenticationResult authResult = null;
IEnumerable<IAccount> accounts = await App.PCA.GetAccountsAsync().ConfigureAwait(false);
try
{
IAccount firstAccount = accounts.FirstOrDefault();
authResult = await App.PCA.AcquireTokenSilent(App.Scopes, firstAccount)
.ExecuteAsync();
Session.Instance.TokenValueFromApp = authResult.AccessToken;
}
catch (MsalUiRequiredException)
{
try
{
authResult = await App.PCA.AcquireTokenInteractive(App.Scopes) .WithParentActivityOrWindow(App.ParentWindow)
.ExecuteAsync();
Session.Instance.TokenValueFromApp = authResult.AccessToken;
}
catch (Exception ex2)
{
}
}
}
Mainactivity.cs
App.ParentWindow = this;
protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
base.OnActivityResult(requestCode, resultCode, data);
AuthenticationContinuationHelper.SetAuthenticationContinuationEventArgs(requestCode, resultCode, data);
}
Manifest.xml
<application android:label="#string/app_name" android:icon="#mipmap/icon">
<activity android:name="microsoft.identity.client.BrowserTabActivity" android:configChanges="orientation|screenSize">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="msal{clientid}" android:host="auth" /> //here i am pasting client id
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="msauth" android:host="{bundleid}" android:path="/{signaturehash}" /> //here i am pasting bundle id and signature hash
</intent-filter>
</activity>
</application>
<queries>
<package android:name="com.azure.authenticator" />
<package android:name="{bundle id}" /> // here i am pasting a bundle id
<package android:name="com.microsoft.windowsintune.companyportal" />
<intent>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="https" />
</intent>
<intent>
<action android:name="android.support.customtabs.action.CustomTabsService" />
</intent>
</queries>