In this article, we are going to implement Blazor WebAssembly cookie authentication using Microsoft Account(external login provider). Part-3 Blazor WebAssembly Cookie Authentication With Twitter Install Microsoft Authentication NuGet Package In API Project: Let's install the Microsoft authentication NuGet Package in API project. .NET CLI Command: dotnet add package Microsoft.AspNetCore.Authentication.MicrosoftAccount --version 6.0.3 Package Manager: Install-Package Microsoft.AspNetCore.Authentication.MicrosoftAccount -Version 6.0.3 Register API With Microsoft Azure Portal: To enable Microsoft authentication to our application, we have to register our app into the Microsoft Azure portal. So following are steps to registering the app with the Microsoft portal. Step1: Go to the Azure portal 'https://portal.azure.com/'. Then select 'App Registration'. Step2: In the 'App Registration' page select the 'New Registration' button. Step3: Configure the