PCWorld claims the U.S. pages for Windows 10 Home, Professional, and Workstation now include a text that reads:

"January 31, 2023 will be the last day this Windows 10 download is offered for sale. Windows 10 will remain supported with security updates that help protect your PC from viruses, spyware, and other malware until October 14, 2025."

The message includes a link to Windows 11 in the hope that users will get the message and upgrade.  It is also likely that after January 31, Microsoft will only sell Windows 11 licences on its website. You can still buy these at third-party retailers and physical copies might be found in brick-and-mortar stores or on the market in the centre of Sofia (last we checked).