Please explain what activation codes are and when they're needed.
Activation codes are used only with (optional) PowerCore and Pro Tools plug-ins.
As the name implies, an activation code is used to activate a plug-in, for the first time. Once a plug-in has been activated, its registration is active, and the activation code can no longer be used. (Think of it an activation code like the gift wrapping paper, you remove to get to the gift inside. Once the gift is unwrapped, the gift wrapping paper serves little purpose and can't easily be re-used again.)
There's no such thing as an activation code for PowerCore hardware or for plug-ins included with PowerCore hardware.
Once a PowerCore unit is connected to or installed in your system, you're able to use it.
As for included plug-ins, once the drivers are installed (and the PowerCore hardware connected to or installed in your system), you're able to use them.