Since Adobe itself has discontinued this product, there are no official fixes to the issue. However, there are some solutions you can implement to unblock Flash Player on Chrome, Edge, Firefox ...

Adobe killed Flash at the end of 2020 ... menu systems or something with decisions/alternate endings. Confirm it works via Ruffle before publishing. You will see a “Test with Ruffle” link ...

So, if you are running a Windows 10 computer, you can have up to 4 copies of Adobe Flash Player: one for Internet Explorer, one for Microsoft Edge, one for Firefox, and one for Opera, respectively.