Yes, it's possible, however, Flash Player will reach end-of-life at the end of the year so it's pointless to create something in Flash at this time. Please research some other technology to use.
See https://theblog.adobe.com/adobe-flash-update/ for Adobe's original announment in July 2017 and https://www.adobe.com/products/flashplayer/end-of-life.html for a mor recent FAQ page
If you want to get into some Flash game development, there's no time like the present and to use the software to make games. If you haven't downloaded it already, Adobe offers a free trial.
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