Answer
Due to a limitation in the OneDrive API, the plugin can only be linked to the entire OneDrive or SharePoint account. The authorization process automatically grants access to the full account, making it technically impossible to restrict access to a specific folder.
Workaround:
If you don’t want to make your entire OneDrive accessible, a recommended approach is to create a second OneDrive account (such as a dedicated "web-only" account or Microsoft Service account). You can place only the folders you want to make accessible through your website in this account, then link it to the plugin. This ensures that only the content you choose will be available via the site.
Note:
Microsoft is developing an "AppFolder" scope, which will eventually allow apps to create and manage files within an app-specific folder rather than the whole OneDrive. Although still in preview and not yet fully compatible with all plugin functions, we’re closely watching this feature’s progress for potential integration.