Not able to Logout in the App

guard let issuer = URL(string: Configurations.issuer) else {
print("Error creating URL for : (Configurations.LogoutURL)")
return
}

    guard let tokenEndPoint =  URL(string: Configurations.tokenEndpoint) else { return  }
    
    //let endSessionUrl = issuer.appendingPathComponent("connect/endsession")
    guard let authorizationEndpoint =  URL(string: Configurations.authenticationEndpoint) else { return  }
    guard let endSessionEndPoint =  URL(string: Configurations.endSessionEndpoint) else { return  }
           
    //UIApplication.shared.open(endSessionEndPoint, options: nil, completionHandler: nil)
    guard let url1 = URL(string: Configurations.endSessionEndpoint) else { return }
  //  UIApplication.shared.open(url1)
    
           let config = OIDServiceConfiguration.init(authorizationEndpoint: endSessionEndPoint, tokenEndpoint: endSessionEndPoint, issuer: endSessionEndPoint, registrationEndpoint: nil, endSessionEndpoint: endSessionEndPoint)
           
    let keychainResponse = keychainManager.getAccessToken()
    
    let token = keychainResponse.message
 
        print("token \(token)")
    
    

    let url = URL(string: Configurations.AuthRedirectURL )!
           let endReq = OIDEndSessionRequest.init(configuration: config, idTokenHint: "access_token", postLogoutRedirectURL:url, additionalParameters: nil)
           
           
           let agent = OIDExternalUserAgentIOS(presenting: presenter)
           
    currentAuthorizationFlow = OIDAuthorizationService.present(endReq, externalUserAgent: agent!) { (response, error) in
        
        if let respon = response
        {
            print(respon)
        }

        if let err = error
        {
            print(err)
        }

}

I'm using above code for Logout but it is not working. I'm using App auth 1.4.0 version. x-code version 12.2. Please help me how to do Logout functionality.

Start with the shown logout flow and compare its OIDEndSessionRequest, OIDServiceConfiguration, endpoint values, token hint, and redirect URL with the AppAuth 1.4.0 API and the provider's logout requirements. Confirm the external user agent reaches the callback and capture the returned error; done means the provider logout completes and the configured redirect is reached.