Please how do I update my software iOS

Update your iPhone, iPad, or iPod touch

• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.6

• If you have an iPhone 6S through 7, you can update to 15.7.1

• If you have an iPhone 8 or higher, you can update to 16.1

Go to Settings > General > Software Update.

Update your iPhone, iPad, or iPod touch using WiFi -

Update your iPhone or iPad - Apple Support

Update using your computer -

Update iOS on iPhone - Apple Support

Hello ozioma51, What model iPhone and IOS do you have? You will need minimum iPhone 8 or later to update to IOS 16.