Cannot update the new version

Hello,

An iPhone 6 (or 6 Plus) will only update as far as iOS 12.5.7. To ensure you have at least that, you can try updating your device. When updating, your device will update to the highest version currently available that it will support, or it will just say it is up to date and won't offer to install anything. If you want to run a higher system version than your current device will support, you need to buy a newer device.

This support article has instructions about updating your iPhone or iPad wirelessly --> Update your iPhone or iPad - Apple Support

You can also use Mac and PC computers to update system software. That is outlined in this article --> Update iOS on iPhone - Apple Support

All those apps require newer iOS versions. the only way you will be able to run them again will be to buy a newer iPhone that is capable of running a required system version. That would be at least an iPhone 6s or higher but if you only upgrade a bit you're likely to be back in the same place in a few months. Get an XS, XR or newer.

You can try using the service interface in web browser instead.