Registering Application in Azure Portal

To register an application in the Azure portal, do the following:

Sign in to the Azure portal using an account that you want to use for sending emails. The account must have an active subscription.
Register an application. For more information on registering applications, see this Microsoft article.
Select API permissions and grant the application the Mail.Send permission of the Application type for the Microsoft Graph API.
Select Authentication > Platform configurations > Add a platform > Configure platforms > Mobile and desktop applications and specify http://localhost as a redirect URI. For more information, see this Microsoft article.
Record the following data required for acquiring an access token: