i have a iPhone 6 that still works perfectly and i would like to use it with my Fenix 5. Why Garmin doesn't allow to use Garmin Connect with iOS 12?
You probably need to ask Apple or Garmin via their support center. This is a user forum, so not likely to get an official response from Garmin. If I had to guess, Apple won't allow it on a phone released…
Right.
iPhone 6 came with iOS 8, upgradable to iOS 12.4.6.
iPhone 6S came with iOS 9, upgradable to iOS 14.6
You probably need to ask Apple or Garmin via their support center. This is a user forum, so not likely to get an official response from Garmin. If I had to guess, Apple won't allow it on a phone released nearly 7 years ago due to security issues and/or Garmin won't support it because there are potentially issues that they cannot easily address.