...
Create a new Application Registration for OneList.
Create a client secret for the application.
Add the following Application Permissions for Microsoft Graph and grant Admin consent to all the permissions.
Mail.ReadWrite
Mail.Send
Copy the Send the following information to IQX OneList Team
Tenant Id
Application Id
Client Secret
Mailbox account (e.g. noreply@yourdomain.com)
More information can be found here:
...