The "Lightroom Downloader" app is only for users of Lightroom (the Cloud version) and who want to download their PHOTOS from the Cloud. (As in the case of cancelling or terminating a subscription.)
Installing any Adobe App (including Lightroom, Lightroom Classic, Photoshop, etc) is done via the install of the 'Adobe Creative Cloud Desktop" app. This app 'downloads' and automatically installs the app (also checking your subscription status.). Of necessity, a paid subscription is required to use the apps longer than a 7-day trial.
Regards. My System: Windows-11, Lightroom-Classic 15.4.1, Photoshop 27.8, ACR 18.4, Lightroom 9.4, Lr-iOS 10.4.0, Bridge 16.0.3 .