That name is already in use in this folder for that user
API returned That name is already in use in this folder for that user. (thatNameIsAlreadyInUse) — typically admin/ops targeting another user's folder.
Why this happens
Same originalName already exists under that parent for the user. Member-facing sibling: That name is already in use in this folder / A file or folder with that name already exists here.
Diagnose and fix
1. Rename the file/folder or pick a different destination.
2. Remove or rename the existing item first.
3. See Folders / My Files library (browse, search, sort).
4. See Enter a folder name for create-name rules.