How can I update iOS 14.6 to the latest version for app compatibility?

Whether, and how far, you can update iOS will depend on which iPhone you have.

Some iPhones that are compatible with iOS 14 can run the latest version of iOS – iOS 18. For others, iOS 15 or iOS 16 is the end of the line.

Update your iPhone or iPad - Apple Support

Updating iOS: common issues and solutions - Apple Community

jimoh70 wrote:

I want to update my iOS 13.5 to latest version

Instead of posting two "me too" replies within the space of a minute, try reading the articles to which links are already provided in this thread.

I want to update my iOS latest version

I want to update my iOS 13.5 to latest version