Lightroom 6 (v6.14) was the final perpetual license version ever released.
Adobe ceased all updates, including bug fixes and new camera support, for Lightroom 6 at the end of 2017. how to buy lightroom 6 standalone
Modern versions of Lightroom and Lightroom Classic are only available through subscription plans , typically starting at approximately $9.99–$11.99 USD per month. If You Previously Purchased Lightroom 6 Lightroom 6 (v6