Uninstall iOS 17 Beta

Those instructions only work for older betas. You will need a computer to restore a previous released version. And note that if you do you will lose all data that you backed up while in iOS 17; you can restore an iOS 16 backup if you have one. See→Apple Beta — Restore Shipping Software

when I googled it it said go to vpn and device management

You wound up looking at an article or information that is more than a year out of date. Things have changed.

You want to refer to up to date articles linked above.

Follow the instructions here: How to uninstall iOS or iPadOS beta software - Apple Support