How do I update software on iPhone
How do I update software on my phone
iPhone 6s Plus, iOS 13
How do I update software on my phone
iPhone 6s Plus, iOS 13
Assuming you have a compatible device, see: Update your iPhone, iPad, or iPod touch - Apple Support
And: If your iPhone, iPad, or iPod touch won't update - Apple Support
If the above Apple articles do not help, please post back with relevant information.
How do I update software on iPhone