Yes my iPhone 6plus won’t update

It appears that you have an iPhone 6 Plus and it is running iOS 12. You have this information in your profile.

You are actually updated. Your iPhone 6 Plus cannot go higher than iOS 12.x.x. To get to iOS 13 and beyond, you need an iPhone that is newer than your model.

Axel F.

That's correct. An iPhone 6 Plus is too old and is no longer supported. Please get a new, current-gen iPhone if you want iOS 13.