how do i change the F3 key on my gateway laptop

[thequestionist]

ok i have a gateway laptop and im playing a game on garrys mod which is zombies and if I want to change a type of zombie I have to press F3 but my laptop the F3 key switches of my wifi connection please help intelligent people out there

 

[jarotech]

Hi, for the WiFi, do you use Fn + F3, instead of just F3.