Cannot be used because I'm on Firefox Legacy.
Why then, was I allowed to download, install it, and waste my time?

If you choose not to make it compatible with Firefox Legacy, then flag it as such in the Add-ons market so people don't waste their time.

I am not happy as this VPN service has affected my online banking access. I have received a notice form Microsoft Security to warn about unknown activity. I am still trying to access other issues that have been created by this specific VPN service. If their tech people in the next few days fail to sort out my issues I will cancel and demand a refund. They were rated high by PC Mag and while I read some negative comments about their service I went ahead with it due to the PC Mag rating. I should have paid attention to the negative comments which I might add also included comments about poor tech service. Additionally unlike other VPN services I have tried because they offered a free trial this one does not (Big mistake in my opinion on my part) Also now I have downloaded their system unlike other VPN services they do not provide a webpage logon to which I can go to find out possible solutions to my problems and as well how to temporarily log off their system, and in my view why? I also changed the settings on Google Chrome to both allow their system and to allow my speakers to work (another problem) and very apparently their Google Chrome extension is bogus as it did not change the problems

Firefox Add-on not working (Firefox 60.0.2 in Ubuntu 18.04).
You can enter your username, but field for password does not respond.

I have mixed feelings here. I totally recommend PIA as a service but not this add on.
Use the actual PIA Client and give this add-on a WIDE berth, it will NOT protect you and WILL reveal your IP address to anybody who is interested. Put bluntly, it just does not work reliably (if at all sometimes).

Sometimes it works, but sometimes it doesn`t, (yet reports that it is connected). - A simple IP lookup reveals all.

Proof:-

https://imgur.com/HnLFbIn (`connected` to london server, but IP lookup showing my Static IP).

https://imgur.com/T6b4mM7 (`connected` to California Server, but again showing my home IP).

A VPN is supposed to anonamize you as one of its primary functions and its clear that with this add-on, the VPN is sometimes not even being connected at all. The most worrying issue is that it reports as being `connected` yet clearly isn`t, which misleads you into thinking you are being protected, when in actuality , you are not.. When first downloaded, this IP look up test (and other similar services), accurately showed the VPN servers IP when tested, but a random test showed it had failed. I guess its possible that reloading the add-on may cure the issue, but whats to stop it failing again? Its not something I would feel happy relying on.