If you were invited to install Firefox on another device (QR code), and you don't currently need Firefox on another device, you can just ignore the invitation.

If your question is about Thunderbird (Mozilla's email program), you definitely do not need an iPhone for that.

I have a problem logging onto Thunderbird using Xfinity's password when asked for a password. I have has at least 20 years using email. The problem started about two weeks ago when Comcast started using two step password verification.

Can you still sign in to your Xfinity mail on their website? I think it's at:

https://xfinityconnect.email.comcast.net/

Yes I can still log onto Xfinity email. The email viewer is not as good as Thunderbird. Currently the bank does not need a pass code for Checking account since it comes to me over my land line by voice, My bank does not keep the webpage for my credit card, This web page belongs to VISA. VISA sends a passcode to Xfinity by email. I input this code into my logon at my bank. Both my checking account and credit card account logins still work. The only thing that is blocked is my logon to Thunderbird. I am not sure why. I don't know how to get Xfinity to send a pass code to Thunderbird. I have read that you might input that passcade when you are asked for a password. No other information was given

Thunderbird really is just showing you your messages, like your Xfinity Inbox in Firefox. You should not need any code from your bank within Thunderbird just to read messages.

Could you double-check the prompt you are getting from Thunderbird to see whether it is asking for a Primary password, or an Xfinity account password, etc.

It Mentions Password for my email account: [edited] @comcast.net. I think I missed one Capital letter on the original password. Is it possible that may be the problem.

Passwords definitely are cAsE sensitive. You definitely know your password because you can sign in using their website. To edit the saved password in Thunderbird, see the steps in the following article:

Password Manager - Remember, delete and change passwords in Thunderbird

Does that work?

I was not able to copy and past the results of the auto configure my settings after removing saved passwords. The message was Incoming server already exists. I was not able to save the configuration.

I lost logging on to Comcast. It appears I need another passcode even if I sellect forgot password.

Sorry, I don't know how to get Saved Logins back in the list after removing them. My thought was to check/edit the one that was there. Someone else probably knows the next step.

And for the two-step code, I think you will need to have your Comcast webmail open in Firefox to get it if you can't receive it by text message.