How can I update my iOS 13.4 so that I can’t use apple store
How to update May ios13.4?
iPhone 6 Plus, iOS 12
iPhone 6 Plus can only be updated as far as iOS 12.5.7. That's it. End of the line.
That means that there are a number of apps that the iPhone 6 Plus cannot run. There will be many more apps that the iPhone 6 Plus cannot run very soon.
The only solution is to buy a new phone......an iPhone 8 or higher so you can run the most up to date version of iOS 16.