@ort_tt , I just tested this api and it worked for me. Let me share the detailed steps below:
- Use Authorization Code Grant Flow to fetch a token for your App from AAD.
- Once you have the code use it to request for an access_token from AAD. make sure the following delegated permission "Mail.ReadWrite" is present on the app registration that is being used here.
- Call the following Graph API.
API: https://graph.microsoft.com/v1.0/userPrincipalName/mailFolders/{id}/childFolders
Body:
{
"displayName": "{Child Folder Name}",
}
This is the ID for my inbox "AAMkADAwZmE5NGU1LWJlYzAtNGE0ZS1hZDI4LWZmNmU0MDdjNzgyZQAuAAAAAABh0v7KYQaiRob9eDRfUq1JAQDBRn5LIsmdTKmOCwZeGkgvAAAAAAEMAAA="
Once you make the api call, you should get status 200 OK and the child folder should be present in your outlook:
Hope this helps.
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