Updating to latest iOS

Update your iPhone, iPad, or iPod touch

Make sure the iPhone has enough Empty Space for the upGrade to download, expand and then install.

Hi Stlfivfoe,

Welcome to the Apple Community.

You might want to back up your iPhone first.

And check you have enough free space for the update process.

Then:

Apple support has an article online (link below) that may help:

You may want to check your settings for automatic updates,

OR

You can follow the guidance to see if you can update manually.

Article: "Update your iPhone, iPad, or iPod touch"

Scroll to: Customize automatic updates

Your device can update automatically overnight while it's charging.

Here's how to turn on automatic updates:

(Follow the steps in the article:)

OR

Check out the other methods in the article.

https://support.apple.com/en-us/HT204204

Hope this helps :-)