acorrding to the page you sent this method is not for chomioum based browser
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This is guide, howto install Adobe Flash Player Plugin version 32 (32-bit and 64-bit) with YUM/DNF on Fedora 32/31/30/29, CentOS 8.0/7.7/6.10 and Red Hat (RHEL) 8.0/7.7/6.10 . Currently only Firefox is supported and you need firefox-x11 launcher or fallback to x11. Wayland and Google Chrome/Chromium is not supported anymore.
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as chrome as built in flash plugin and that what i am looking for
did you closed brave before install flash
check this post
also this