For security reasons, if you have lost access to the email address associated with your Mozilla account, you cannot recover the account or change the email address. The recovery code is sent to the primary email address on file because it is the main way to verify that you are the account owner.

This is a security measure to prevent unauthorized access to your synchronized data like passwords, bookmarks, and history. Without being able to receive that verification code, there is no way for Mozilla to confirm your identity.

What you can do: Check other devices. If you are still logged into your Mozilla account on another device (like an old computer, tablet, or phone), your synced data should still be there. Search for a recovery key if you had previously set up a "recovery key" on your old account, you might be able to use it to recover your data.

So i have my account recovery key how can i use that to get access to my sync data ?

Here's how to use your recovery key to regain access to your sync data:

1. Initiate a Password Reset

Go to the Mozilla account sign-in page. Click the Forgot password link. Enter the email address associated with your Mozilla account and click Continue.

2. Enter the Recovery Key

Enter the full 32-character key into the provided field.

3. Create a New Password

Once you've successfully entered the recovery key, you'll be able to create a new password for your account. After you set your new password, a new recovery key will be generated.

4. Re-sync Your Devices

Sign in to your Mozilla account on all of your devices (desktop and mobile) using your new password. Your synced data will begin to download and reappear on your devices.

https://support.mozilla.org/en-US/kb/how-change-or-reset-your-mozilla-account-password#w_password-reset-with-recovery-key

https://support.mozilla.org/en-US/kb/reset-your-firefox-account-password-recovery-keys#w_how-to-reset-your-password-with-your-account-recovery-key