Adobe now offers the current and ONE older version via the online program manager Go here for all older links https://prodesigntools.com/adobe-direct-download-links.html -Prodesigntools is an official Adobe partner, and the links go to Adobe, not a 3rd party site
IF/When you do have a download, be sure to copy it to AT LEAST one external device -you should ALWAYS keep a copy (or two!) on an external device -since Adobe DOES SOMETIMES REMOVE OLD VERSIONS FROM THE SERVER -a usb flash drive or external hard drive, or write to a CD or DVD
Adobe does NOT do support by email, so beware of answering anyone who sends you a private message -click for more information about scammers https://tinyurl.com/10791730
cc 2021 is the last version compatible with your os. for that (and cc 2020), you must contact adobe support*.
if you can use cc 2019, use @John T Smith's prodesigntools.com link
*
use a browser that allows popups and cookies and contact adobe support by clicking here, https://helpx.adobe.com/contact.html?rghtup=autoOpen in the chat field (lower right), type AGENT be patient, it can take quite a while to reach a human