Another thought: Maybe they're looking for the 12th volume specifically. The 12th volume is "Morgoth's Ring", correct? It's a bit harder to find, sometimes out of print. So perhaps suggest checking used bookstores or online retailers for affordable used copies. Also, maybe look into university libraries or interlibrary loan services.
While the allure of a free digital archive is tempting, the text of The History of Middle-earth is complex, often requiring navigation between footnotes and appendices that can be cumbersome in unofficial, poorly scanned PDF formats. For the best reading experience—and to respect the copyright of the Estate—utilizing library lending apps or the history of middle earth volumes 112 pdf free