I can’t download many app on my iPhone 6 how can i ungraded the phone

iPhone 6 is forever limited to iOS 12.

There are no hardware upgrades.

For newer iOS, your options are a newer (used, refurb) or new iPhone.

This is not possible. iOS 12.5.7 is as far as the iPhone 6 can go.

You need a new iPhone......an iPhone 8 or higher model.

Delete apps for storage

damilare210 wrote:

I won’t too upgrade it too ios14.00

Here is the official iOS upgrade info for iPhone 6 and iPhone 6 Plus—how to get iOS 16