I want use ios14 in my iphone 6

An iPhone 5s, iPhone 6, or iPhone 6 Plus isn't capable of 13 or above; they require at least 2GB of RAM. Try downloading the applications to a newer unit on the same Apple ID first.

(239506)

iPhone 6 cannot be updated any higher than iOS 12.5.7.

You need an iPhone 7 to install iOS 15

You need an iPhone 8 or higher model to install iOS 16

Update

Nope