New-MgUserEventAttachmentUploadSession
POST /users/{user-id}/events/{event-id}/attachments/createUploadSession (v1.0)
Module: Microsoft.Graph.Calendar
Permissions
Delegated (work or school)
- Calendars.ReadWrite (least privilege)
- Mail.ReadWrite
Delegated (personal)
- Calendars.ReadWrite (least privilege)
- Mail.ReadWrite
Application
- Calendars.ReadWrite (least privilege)
- Mail.ReadWrite
Source: Microsoft Graph PowerShell SDK metadata
Confirm property-specific permissions, Entra roles, licensing and ownership requirements in the official documentation. SDK metadata outside the verified sample is not independently certified.