How do I authenticate my sync account?

I have used three authentication programs to get into my Sync account, but I cannot get any of them to generate an authenticationcode that Firefox will accept. I set up this account before two step authentication was required, and I have not been able to get into the account since that was required of all accounts. I signed it one time and it asked me to click on link on a email they said they were going to send me. I've checked my Spam folder and my inbox folder, and I have not been able to find the email else was supposedly sent to me. Unless I can find a way to authenticate my count, I am basically locked out of my account and I cannot get any help to reset the account. Can someone suggest a way to get the authentication program to work? I have tried everything and nothing seems to work.