In addition to the EOL killswitch, Adobe have gone out of their way to remove downloads for previous versions of Flash Player from their website.
# For instructions on how to specify flags on other systems see Downgraded Firefox: Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome -allow-outdated-plugins 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe' -allow-outdated-plugins
Simply run Chrome with the -allow-outdated-plugins flag: # On Windows: If you’re using any version of Google Chrome, up to and including Google Chrome 87, you might not have to install anything at all! You should be able to continue to use an older version of Flash Player which was immune to the effects of the EOL Killswitch. You can find a more thorough list of emulators in the Flash Player Emergency Kit. Ruffle even has an online demo if you’d like to see it in action before installing. Two mature Flash Player emulators are Ruffle (ActionScript 1&2) and Lightspark (ActionScript 3). It’s still possible to run Flash Media (.swf files) without actually using Flash Player.