Do you need to roll tech attack for all tech actions?

In the core rulebook p. 79, it reads:

TECH ATTACK: The statistic used to make tech attacks and to take most tech actions.

So from that, I understand that we have tech actions and some of them, most of them BUT not all of them require a tech attack throw.

The tech action (p. 70) “scan” and “lock on” doesn’t mention any tech attack throw while for invade it does say that an attack roll is necessary.

In my group, scan and lock on are considered tech attack. Does someone knows which one it is?