How do I use the "no contact" rule to get him back?

Like, after the first date? You can contact afterwards by giving a short text saying you had a good time and you'd like to see him again.

And if it terms of having an argument, that doesn't work. It gives people more time to stew in anger. Sometimes, people need time to cool off, and that should be communicated. But to maintain a relationship, that's not really the best way to go about it.