nodejs-send-emails-using-microsoft-graph-api

Register the application

Sign in to the Azure portal. https://portal.azure.com
If you have access to multiple tenants, use the Directories + subscriptions filter in the top menu to switch to the tenant in which you want to register the application.
Search for and select Azure Active Directory.
Under Manage, select App registrations > New registration. Enter a Name for your application then Select Register.
Under Manage, select Certificates & secrets.
Under Client secrets, select New client secret, enter a name, and then select Add. Record the secret value in a safe location for use in a later step. Under Manage, select API Permissions > Add a permission. Select Microsoft Graph. Select Application permissions.
Under User node, select User.Read.All and Mail.Send, then select Add permissions.