got a 6 plus with 12.5.6. need 14. when I get to software updates it says its up to date

An iPhone 6 Plus cannot update past iOS 12.5.6. You need a newer phone.

You are asking for iOS 14 because there are a few apps that do not work on iOS 12.5.6. You should contact the app developer for the same.

Ask the App developer to release the app for lower iOS versions also. Netflix has done it.

If you are experiencing any difficulty with third-party apps then please contact the app developer directly --> How to contact an app developer - Apple Support