Adobe has ended support for Flash Player at the end of 2020 and encourages content creators to migrate any existing Flash content to new open formats, such as HTML5, WebGL, and WebAssembly. For more information, see Flash Player end-of-life.
Check out Adobe's detailed announcement: Flash and the Future of Interactive Content.
You may also look at the help page https://helpx.adobe.com/acrobat/using/flash-player-needed-acrobat-reader.html for more information.
Regards
Amal