How can I update my iPhone?

Hello ~ Your iPhone 6 cannot be updated any higher. If you need a higher version of iOS you will need a newer iPhone. Take a look at the black line above and click on iPhone to see your new choices or if you choose to purchase a second hand device please take the time to read this information:

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Also:

The All Too Common SAD Reality of Buying a Used iPad/iPhone

Also it is best to post once and wait for help . Posting and reposting is confusing plus you have marked your own post solved thus reducing your chances of help.

~Katana-San~