Community-maintained repositories like the Internet Archive often host original OEM ISO images for specific languages.
You cannot add or change display languages; the system is locked to the original language (e.g., English, Spanish, Russian). How to Download the ISO for Lenovo
This version was sold only to manufacturers like Lenovo at a reduced price.
Windows 8.1 Single Language with Bing was a unique, low-cost operating system pre-installed on many Lenovo laptops and tablets to compete with affordable Android devices. Because it was an OEM-exclusive SKU (Stock Keeping Unit), finding an official ISO download can be difficult, as it was never made publicly available through standard retail channels or the Microsoft Media Creation Tool.