Really need some help; please..

[Mostyn]

OK, I have an Apple Mac, an Apple iPad; and an Apple iPhone 5s.

The Problem.
Two Factor Authentication Update on iPhone!

Updated and signed in to Two Factor Authentication; then was asked to sign in to iCloud on one of my other devices (which I've done several times) BUT.. they keep asking me to sign in again = Continue - OK done also phone opening code done. Then I get : Go to one of your other devices, signed in to iCloud to approve this phone!
I've tried to accomplish this many times; without success.
Can anyone walk me through the system to get this done and completed?
How do I approve my apple phone on my Mac or Ipad ??
Help appreciated

 

[Jjayf]

I believe you go into your iCloud account in the settings and approve the phone.

 

[Mostyn]

I believe you go into your iCloud account in the settings and approve the phone.

Yes,
Done that several times, it won’t work for some reason.