Hello Julián José López Arellano,
Thank you for reaching out to Microsoft!
Yes, you are correct. The provided JavaScript code is focused on deleting the event using the Microsoft Graph API. The HTTP DELETE request send to Graph API endpoint will remove the event from the calendar, but it does not provide an option to update the email body of the cancellation notification.
To send a custom email notification upon event deletion, you would need to manually send an email with the updated content.
Hope this helps.
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