It only takes a few simple steps to figure out what version of software you are running on your iPhone, please follow the steps below to find out what software version you have
Go to the settings app on your iPhone
If you do not see "Settings" in the top, you might be on a sub-setting page, click either "Back" or "Settings" in the top left until you get to the main settings page. You can tell because it will say "Settings" in black font in the top left and have your name or your phone's name in the middle
Scroll down and click on "General"
On this page, look for an option "About" - click it
On this page you will see a row labeled "iOS Version" - the number to the right of that starts with either 26.x or 18.x - the numbers after the first number do not matter, just the first number.
The first number tells you what software version you have.
Please note, if you have a software version less than 18, we strongly suggest you investigate if you can upgrade your phone's software as there are significant security benefits of being on at least iOS version 18