There's is nothing Firefox forum users can do to help here. Since the reset goes to a dead email that means that account is a lost account and there is nothing more that can be done to fix that.

Unfortunately, without access to your Firefox Account primary email address, you can't click the verification link to approve a replacement address.

Is there any possibility of your Juno email getting forwarded to your Gmail address or have you lost access to Juno completely, so you can't set that up? (or maybe they don't allow it?)

If nothing else resolves the issue, you can create a new Firefox Account with a new email address.

See also:

• https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information
• https://support.mozilla.org/en-US/kb/forum-response-firefox-sync-verification-email-faq