Tutorial instructs to use Testnet, but app requests switching to Ignition

## Description
Hello Fuel team,

I'm following the tutorial on [Building a Frontend for the Counter dApp](https://docs.fuel.network/guides/counter-dapp/building-a-frontend/#modify-the-app), and I encountered an issue that seems to contradict the instructions.

The tutorial clearly mentions using the Fuel Testnet, but when running the app with the provided code, a modal appears requesting a network switch to Ignition (see attached screenshot).
This behavior is misleading for users trying to complete the tutorial as instructed.

It seems that either:
- The frontend code defaults to Ignition regardless of the tutorial's setup, or
- The documentation needs to be updated to reflect the correct target network (if Ignition is indeed now the intended one)

I believe a fix is needed either in the tutorial content or the example code to align with the intended test network.
Thanks for the great work, and looking forward to clarification!

## Screenshot