While Flash is no longer available to download since December 31, 2020 & Adobe starts blocking Flash content from running on browsers altogether on January 12, 2021,
you still can play Flash content on your browser with these methods.
Ruffle is a Flash Player emulator built in the Rust programming language. It will detect all existing Flash content on a website and automatically "polyfill" it into a Ruffle player, allowing seamless and transparent upgrading of websites that still rely on Flash content.
If you want to view and play Flash on this website, then you can install Ruffle's browser extension.
Please visiting Ruffle's website and see the "Installing the browser extension" section for tutorial part, and "Downloads" section to download the version of extension you want for your browser.
You also can use "Basilisk Portable With Flash Player" to play Flash content on browser.
Basilisk is a free and Open Source XUL-based web browser, featuring the well-known Firefox-style interface and operation.
This version of Basilisk browser is 2020.11.25,
the last Windows 32-bit build from https://basilisk-browser.org/.
A Plugins folder containing Flash Player 32.0.0.363 (NPAPI, Windows 32-bit) was added to the main program folder. The Flash Player was hacked to prevent it from contacting Adobe's servers, meaning that Adobe has no ability to disable this Flash plugin in the future.
If you want to view and play Flash on this website,
then you can download "Basilisk Portable With Flash Player" from here.
And open the portable browser in the zip to view pages that contains Flash.