how to stop update 26.1 from updating

Settings, General, Software updates, turn off auto update and auto download.

If the update is already showing,

1. Go to Settings > General > [Device name] Storage.
2. Find the update in the list of apps.
3. Tap the update, then tap Delete Update.

However, I recommend updating, but up to you.

Stick with 1 post and add additional details you want to provide there. You will find that duplicate posts are commonly deleted and you may lose any information that was provided in one of them.

How to stop an update from downloading? - Apple Community

oh well he's been advised twice now!