I want to enable or use Backspace to switch back to previous page that I visited previously in the Firefox browser on Ubuntu. For example, if I am using any browser on Windows, I can use Backspace instead of back button in browser to go to previously visited page.
It's not an OS issue, but this way you will get it to work
Open your Mozilla Firefox browser, and in the address bar, type
about:config. Then search for
browser:backspace_action. Since the entries are in alphabetical order, it's essy to look for it. When you have found it,
double click on it and change its value to 0 from 2. That's it.
You will find these steps in detail in the following article (see link)