Impossible to get last iOS update on Apple iPhone 6 Plus 128 Go Gold

Hi,

I bought a new iPhone 6 Plus 128Go on Rakuten but when I do a factory reset, I cannot get a version of iOS higher than 12.4.9

Even with iTunes it says I have the last update.

I also have an iPhone 6 Plus 16Go and my iOS is more than 12.4.9.

The result is I cannot use my new phone which I need to record videos.

How can I install the last version ?

Regards,

Pierryck

+33 663664119