How to install Firefox on UBUNTU? And how to Import files into UBUNTU?

Please follow the guide here. https://support.mozilla.org/en-US/kb/install-firefox-linux

I could only do item 1. How do you do items 2+  ? And which of those sites require an athorization key or password. Ubuntu still doesn't have a link on those sites for forgotten passwords etc.

Could you do 'sudo apt install firefox'?

Same issue with no "Forget Password" link...

Hi, nothing requires authentication.

Could you please clarify what issue you are experiencing? Which command do you have trouble executing, and what output do you get?

OK, will do tomorrow, as I have already shut down my PC. I had numerous places where it asked for my authorization codec or password.