Running Flash Applications past the End of Life date is not recommended nor supported.
Adobes last Flash update included a kill switch disabling any flash content on its flash player platform past January 2021.
1) Install Waterfox from https://www.waterfox.net/
2) Download Flash from Internet Archive: https://web.archive.org/web/20210000000000id_/https://fpdownload.adobe.com/pub/flashplayer/latest/help/install_flash_player.exe
3) Install Flash and enable "Never Check for Updates".
4) Download Flash Patcher from Github: https://github.com/KuromeSan/FlashPatcher/releases/download/v1.6/Flash.Patcher.exe
5) Run the Flash Patcher. Your virus defender might warn against that.
6) If you do not want to be asked to uninstall Flash by Windows remove "C:\Windows\SysWOW64\Macromed\Flash\FlashUtil32_32_0_0_465_Plugin.exe"
7) If Windows Updates removes your Flash installation, you might need to repeat the above.
Do not use this workaround for anything else than to connect to trusted website.
Of course the best approach would be for me to learn Java Script or HTML5 programming and update this website or to find someone willing to do this.