I made sure that the Adobe Flash Plugin is activated but I still can't find it.
Now, I can't listen to Google Translate how to pronounce a word.
Is this an issue with Ubuntu? Or is this just an updated version of Google Translate?
Solution 1: For apt Firefox, install following plugin.
sudo apt install browser-plugin-freshplayer-pepperflash
Solution 2: Install snap Firefox. By default, sound button works.