Stock Transfer is not available in this version of OCTO Ops. The Coming soon badge on this page refers to the Stock Transfer screen itself, not just to this guide — there is no Stock Transfer page you can open in the application yet.
See Warehouse for your stock instead. Stock Transfer still appears in the left navigation under Inventory. Opening it shows a page saying it isn't available yet; Inventory is being rebuilt and its screens arrive in later releases.
Who can open it: Inventory › Stock Transfer › View.