Lists the supplier branches already saved in Zuper for this provider. Each saved branch is a Zuper vendor linked to the provider, so the list is read from Zuper without calling the supplier, and every record carries a supplier_provider_details block with the branch code and the job account used for orders. Results are paginated with page and count and ordered with sort_by and sort (newest first by default); this endpoint does not use limit or sort_order. Unlike most endpoints, the response has no title, message is always success, and there is no current_records. Use Get Live Supplier Branches to see branches you have not saved yet. The provider must exist and be CONNECTED; otherwise the request fails with 404 (unknown provider) or 403 (not connected or reconnect required).