Unfortunately the problem is not resolved viz:
As long as you remember your Apple ID password and still have access to one of your trusted devices, you can sign in and create a new Recovery Key.
- Go to your Apple ID account page.
- Sign in with your password and trusted device.
- In the Security section, click Edit > Replace Lost Key.
Keep your new Recovery Key in a safe place. Your old Recovery Key won't work anymore and you can't use it to reset your password or access your account.
Unfortunately there is no longer an option to "Replace lost key" as shown in section 3.
As two-factor authentication was turned on using my iPhone 6SE I never received a Recovery Key which could be used on my older iPhone and I am unable to generate one now. I appreciate that times move on, with an alarmingly short time scale, but the 3GS is still a workable phone, and as I live in a rural area that has poor coverage, I have to keep three phones using different service providers up and running to ensure that cover is available when required. Even the landline only provides 2.4 mbs on a good day.
Any suggestion, other than moving, would be welcomed.