No one here will give you money for a new phone.
Apple’s Worldwide Developers Conference to kick off June 10 at 10 a.m. PDT with Keynote address
The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.
The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.
No one here will give you money for a new phone.
The iPhone 6 and 6+ is not compatible with iOS 13 or 14 and above the only iPhone6 models that are compatible are the 6S and a 6S plus
The iPhone 6 is not compatible with iOS 13 or 14.
An iPhone 6 cannot update past iOS 12.5.2. If you need a newer iOS version, you will need a newer phone.
Then what should I do for payment
If that method of payment requires a version of iOS higher than 13, you will need a newer device.
Are you giving money to purchase newer iPhone
How to install iOS 13.4 in iPhone 6