Argon One v2 What GPIO pin is the fan

This info should be in the description of the product…
Not sure why it’s this difficult to find an answer.
I’m using raspi-config to set the fan GPIO pin…
What pin is the fan on?

The last 4-5 pages of your manual contain information on it.
You need to install the Argon One Pi 4 script.

curl | bash

Then run

argon-config # or argonone-config

The default fan speeds are:

55C 10%
60C 55%
55C 100%

It also has instructions on if you want to use an IR remote to turn it on and off at the end of the manual.