Let us do all that work for you and just lean back...
Microsoft 365 Exchange Online: Synchronize subfolders or categories
In the "Advanced settings" of a sync.blue® connection, if a subfolder is defined as the sync source or target, sync.blue® will now automatically create this folder when needed. In newer versions of Outlook, contact folders are also referred to as "categories".
This subfolder must be created either by sync.blue®, Outlook for Windows, or Web in order to be synchronized. Folders created differently (e.g., via Outlook for Mac) unfortunately cannot be synchronized due to a Microsoft bug.