como instalar flash player 22 en windows 10

Depends on the browser.  Microsoft embeds Flash Player in IE and Edge browsers on Windows 10, and all updates are released by Microsoft via Windows Updates.  An option to revert to an older version is to go to Installed Updates and locate all Flash Player updates and uninstall them.  This is not ideal, as the updates will simply reinstall, since Microsoft automatically installs updates on Windows 10, and depending on how new your computer is, it may not have the update available. For example, Flash Player 22 was released in June, July and August of of 2016.  If your machine is newer than that then it won't have the updates to remove to get to the older version.

For Chrome, Google also embeds Flash Player in Chrome and unless Chrome is launched with specific parameters, telling it which Flash Player file and version to load, it's always going to load the most recent version.

For Firefox, you can just uninstall Flash Player from the Control Panel.

It's odd that a vendor would make a training program that requires a specific old, unsecure version of Flash, especially when Microsoft has embedded Flash Player in IE since Windows 8.1, and Google has been embedding Flash Player in Chrome for well over 5 years.  Seems to be poor design from the training program vendor.

Additionally, most browser vendors  block old versions of Flash, and do this to ensure only the latest, most secure version of Flash Player is being used.  This is to protect your system from malicious actors.

With that said, if you still need to install old version of Flash (which will most like only work on Firefox, and even then you'll need to explicitly tell Firefox to load the old, unsecure, version), old versions are posted at Archived Adobe Flash Player versions