Как установить 15.8.5?

15.8.5 is no longer available, 15.8.6 is available for qualifying phones

Update your iPhone, iPad, or iPod touch

• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.8

• If you have an iPhone 6S through 7, or SE 1st generation, you can update to 15.8.6

• If you have an iPhone 8 or X, you can update to 16.7.14

• If you have an iPhone SE (2nd generation or later), or 11 through 17, you can update to 26.2.1

Go to Settings > General > Software Update.

This link will show you how to update your iPhone, iPad, or iPod touch using WiFi -

Update your iPhone or iPad - Apple Support

This link will show you how to update using your computer -

Update iOS on iPhone - Apple Support