Does Azure "App Registration" with the Graph API to create calendar events cost anything?

Question

Goal

I want to create an application in the App Registration service to use the Graph API service to only create events in the Outlook calendar.

Doubts:

Can I use a regular account for this? (@outlook.com) Is the free account enough or do I need it to be MS 365? Does the activity described above involve any costs?

Answer 1

No costs involved, but by default guests can not register apps unless given an elevated role:

https://learn.microsoft.com/en-us/azure/role-based-access-control/role-assignments-external-users

https://learn.microsoft.com/en-us/security/zero-trust/develop/app-registration#who-can-add-and-register-applications