Hi System,
Thanks for reaching out on Microsoft Q&A!
Normally, a site for a private channel is only provisioned as soon as one clicks the ‘Files’ tab. Basically the same behaviour applies to a channel folder in ‘standard’ channels.
However, when it comes to API calls, clicking the ‘Files’ tab isn’t something you can do. But, there is a possibility to mimic this by calling the ‘filesFolder’ API after you’ve created the private channel, triggering provisioning of the site.
Please find the details for the ‘filesFolder’ API through the link below:
https://learn.microsoft.com/en-us/graph/api/channel-get-filesfolder?view=graph-rest-1.0&tabs=http
Please click ‘Accept answer’ if you think my answer is helpful. Feel free to drop additional queries in the comments below!
Kind regards,
Sonny