Flash player's support has ended of December 31 2020, and the plugin will not work anymore on January 12 2021
See the Debian wiki page
https://wiki.debian.org/FlashPlayer
As most people are aware Adobe has stopped support for Flash on 64bit, no one knows for how long. Do not use the 64bit flash beta, it has major security problems.
Adobe Labs - Downloads: Flash Player 10 for 64-bit Linux
Quote:
We have temporarily closed the Labs program of Flash Player 10 for 64-bit Linux, as we are
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